Paid around 30$ for this little gem
 
it has the MA900's sound signature, but at much better price and less requirements. 
It has angled drivers, which makes for a pretty good stage. it is very light, comfortable, and overall an excellent all-rounder.
the bass is of course elevated more than it should be, but not too much (certainly not for bass-heads)
the mids are the magic here... Ambient is so good with this one.
the treble is rolled off, well, same as the MA900's.
 
While it may be a little bit less refined in comparison to its bigger brother, it is still so good... I rank it as my #1 for TV & Movies purposes.
There wasn't even a need for a burn-in... it sounded great straight out of the box.
 
In short, 
- I didn't imagine i'll get so much for the 30$ (!)

For those if you who know me, you know i prefer the FR curve to be as neutral as possible. 
I have the Etymotic ER4s (ER4p with Etymotic's 75 ohm converter cable), had the HF5, and tried many other IEMs.
 
I'm Listening sometimes via my desktop amp. (the "Shiit Fulla"), and sometimes straight from my "Samsung Galaxy S4" cellphone (when commuting).
 
While i pretty much enjoy hearing everything from my ER4s (sometimes I prefer using the 'p' version (w/o the converter) when i desire a tiny bit more warmness to the sound),
It is sometimes just too clinical and analytical sounding for use with "normal" (mainstream) music / TV.
Also - the piano timbre sounds sometimes just too light sounding / bright with these (for me at least.. I think it has to do with the BA drivers vs. dynamic ones)
 
I tried to have 2 earphones then, when the other one should serve my other purposes;
But something like "Zero", "Havi", "Sennheiser", "Westone" and even "Shure" is just too warm for my tastes.
I then tried "Rock-It sounds", "VSonic", "HiFiMAN" and more.. but it was almost the same (analytical), or just not detailed enough (w/recessed treble). 
 
So i didn't find peace...
 
Then, a thought came into mind... why not try the new model from Etymotic, which supposedly caters for more genres?
Not even 2 minutes later, I bought my unit from an authorized Ety dealer I found on eBay (paid 72$ after ship.), and 2 weeks later (this was an intl. shipment) it has arrived.
 
Einstein said that physical things are relative; 
That said, I will base my characterization of the MK5's with having the ER4 acting as the baseline.
 
While the MK5 is less detailed than the ER4s, with less treble quantity (ofc.), it is lighter, smaller, has a thinner cable (not coiled nor twisted) -which weights less BTW.
Also, it seems to me that it exudes a wide sense of stage (for ex. listening to "Radiohead" is a possible pleasure now... also, i can enjoy ambient styles more)
 
the bass is bigger than any other Ety earphone in the series, but still much lower than any of the "bass" earphones
the lower mids are somewhat fuller, which is better for mainstream songs and/or piano (in my tastes)
The upper mids are slightly less forward, but still sound very clear
The treble doesn't have the air the ER4 has, but it's not too far away from the 'p' version (in quantity)
 
They are light and comfy
I'm not sure regarding to the cable as of yet... it is thinner and lighter
same goes for reliability... time will tell i guess.
 
Overall, i'm very happy with it
for the price paid? WOW...
 
My verdict, you ask?
Highly Recommended