I bought these from Focalprice.com for all of $3.51.  A lot of head-fiers here love these for their bass richness and I bought them just to experience the bass.  Man, I have to say, these little suckers, put out some pretty nice bass.  That was pretty surprising.  Unfortunately, everything else sound quality wise is pretty crappy.  They have a hollow sound, mids are recessed, basically not much more than glorified bass cannons.
 
The included tips make me cringe.  All but the blue ones are basically the same exact size: small.  They are literally the thinest tips I have ever felt.  Even the blue ones are too small to isolate much.  The shells may be real wood, but that's about where the finer side of things end.  Strain reliefs are good, cabling's a bit thin for my tastes.  The open air port in the back of the shells don't help the hollow sound and lead to some rather bad leakage in my opinion. 
 
Besides bass novelty, I rarely reach for these.  I've been meaning to epoxy those air ports, but never did get around to it.  Just don't think it's even worth it.

This was my first pair of IEMs before I even knew to call these "IEM".  Also my first real introduction to good sound quality.   Shortly after getting back stateside, I was browsing reviews on Head-Fi.
 
Let me first say that I did not buy these in the United States.  I bought them on a trip overseas in Hong Kong.  So the carrying case was not the leather pouch that these originally shipped.  I instead got the aluminum 3"x3" carrying hard case (I have gripes about this as well).  Packaging wise, it was pretty typical plastic fair with the phones prominently visible at the top of the rectangular plastic carton.  No real wow factor here other than the sleek professional looking paperboard labels and inserts.
 
At first I found the memory wire ear loop portion to be fantastic and wondered why other manufacturers weren't using the same design.  Over the course of the past few years, I've grown to hate and love the memory portion of the wire.  Unfortunately, I'm frustrated with it now.  It's hard to bend into a new comfortable loop without some portion pinching my ears.  The rest of the wire is equally frustrating as it also has a semi-memory characteristic.  So if I wear these on the streets of downtown Chicago, people usually give me weird stares.  At one point, a guy commented that the cord's loopy shape bent outward from my chest like a "penis".  I felt utterly embarrased and quit using them for nearly a week afterwards.  I now avoid any memory wire like the plague.  (I'm sorry for those who still love the memory wire.)  The cable is detachable and as of this writing, UE still sells the cable set ($20 USD) on their website.  At some point, I'm going to recable mines.

Other than that, they fit beautifully.  I use the medium tips since the large ones are too large and hurt my ear canals.  The foam complys don't last since I build up earwax fairly easily and those foam tippies are pretty nasty after a few days.  Due to a certain accessory case, I've since lost one of the pair of silicone tips.  The tips themselves are quite nice and it has set the standard thickness I look for in canal tips.  They aren't too thick and offer enough squishiness and flexibility to help isolate quite a bit of background noise when worn.  I only wish I had some medium double-flange tips. 

The shells are hard plastic, but great quality.  I treat these like little babies, so they've never seen any extreme abuse, though some things I've done wearing these around might seem extreme (like wearing them in a very hard thunderstorm).  They seal so well, that I wasn't too worried about water getting in.  The only gripe I have with the casings, is the ease to which the pipe opening of the sound barrel can collect bits of ear wax and other particles.  It's so frustrating hard to clean them with the included tool and often times I resort to a thin paper clip.  Even then, I still have bits of ear wax trapped in there by the edges of the internal filters.  I swear these has a impact on how they sound, though perhaps not significant.
 
Sound quality, these blew me away.  They have the clarity I now expect from budget IEMs based on armature designs.  They are fairly balanced, analytical and detailed just the way I like them.  I could hear instruments in various tracks ranging from rock, to opera, to classical instrumentals, to electronica.  These brought a new definition to the word "music" and completely revived my love of classical music.  Bass is controlled, very good transition between beats, precise and not bloated.  They also have a nice roundness to them that I'm rather fond off and haven't yet heard in any dynamic canalphones personally.  There is no detachable veil and they are easy to drive with the various portable sources I have.
 
To first timers, I'd highly recommend turning down the volume on your portable before plugging these in.  Otherwise, you might hurt yourself or become temporarily deaf in both ears.
 
The aluminum hard case that I got I feel is to small to hold the tips, cleaning tool, and the phones.  I have to severely bend the wire and jam them in to close the lid.  The lid also doesn't lock in place, so a simple drop and everything goes all over the floor.  I feel the original leather pouch that shipped with these are and were far superior to anything that were included later as "carrying cases".

Of course, being that I bought these years ago, Ultimate Ears (UE) no longer offers these Super.fi 3 Studio phones on their website and short of a few auction sites and perhaps here at Head-Fi, you'd be pretty hard pressed to find a UE pair.  However, these exact ones (with bi-flanges) have been rebranded as Altec Lansing UHP336.  Unlike the black pair I have, the UHP336 is dark gray, matching the dark gray tips.  They can usually be found on Amazon for $30-$50.  As of this writing, they are selling for $48.  Personally, I wouldn't pay more than $40 given that they can usually be found for cheaper than $40.

It seems the UE 600s would a successor to these and they are priced at $100 as balanced single armatures.  How do they compare, no clue.

If you're into good sound quality, want a great starting budget set, and want that detailed, analytical, clarity from your future canalphones, these are a great pair to start off with (or rather the Altec Lansing UHP336).

I originally bought these as a cheap headset for mainly gaming use.  Bought online for $21 shipped.  Marketing might say "military spec" construction, but it's not even close.  The entire headset is constructed of plastic.  I could easily wobble the cups and headband.  I'm pretty sure excessively doing that could I could quickly break and detach the cup shells, cable, and headband.  There is no metal band in the headband portion, I only wish.

I did like how comfortable they are.  They don't clamp down all that hard and those earcups go around my rather large ears.  So no more crimped ears that hurt for hours on end during long gaming sessions.  The pads feel like suede and over time it will collect a bit of dust and other particles.  Cleaning them is a bit of a chore.  The boom mic is extendable and folds back up in the recessed nook in the left side headband.  The cable reliefs are hard plastic and rather unwielding.  I don't advice bending those cables at the joints at any extreme angle.  The cable themselves feel rather tough and through some accidental sittings, they can definitely stand up to more abuse than the rest of the set.  I actually had my chair's legs on the cable quite a few times and I sat there oblivious until I had to move the cord.  No dents or crimps in the cord.

Sound wise, it's nothing even a newbie audiophile here would call "great".  Due to the design and the use of rather weak plastics (and general lack of isolation), these are more of a semi-open design than a truly closed design.  Although I haven't tried the 377s, I'd wonder if there are any differences at all.  Isolation is pretty poor.  No sound and just having them on, I could easily pick up normal conversion in the same room and adjoining rooms.  Treble definitely does not have the clarity you would find at the $50 or $100 level, but it's also not veiled or really lacking.  It just pretty normal inoffensive sounding, no shrills, no wow factor.  At first, I felt the mids were a bit recessed and overall had a hollow sounding signature, especially in the lower treble, mids, and upper bass.  Over the past few months, they've warmed up a bit.  I don't seem to notice the hollow signature.  Bass is well, pretty average.  It's not bloated (thank goodness), but also not very impactful.  Again probably due to poor isolation and the (unintentional?) semi-open design.  Control and speed is pretty good, though I don't have yet to try any very fast bass tracks on this set.

In the end, the ultimate question is whether I'd recommend the set or buy another for myself.  I would recommend it if you're looking for a comfortable budget headset for gaming and don't expect a great sound quality with isolation out of them.  I have recommended these to friends already and if my current pair dies, I'd pick up another pair to replace them.  I do wish the plastics used were of a higher quality and they isolated better.