Have had these for almost two years. Though I'd at least write a few basic impressions.
 
First, the intended gaming and media use:
Well, I have to say I've found them excellent. Voices are clear, environment sounds are crisp and the lower end does subsonic rumbles and concussive thumps equally well. The phones actually still make me check if I have left my external subwoofer turned on from time to time. Headphone surround with the included sound card and drivers works decently, though I haven't had much to compare with. Borderlands 2 sounds open and wide, Bioshock 2 sounds confined and eerie as hell. They are comfortable enough for a weekend of Civ 5. DiRT 3, GRID 2 and Shift 2 have worked well without making engine sound annoying.
 
There are probably other gaming phones that sound about as good in the price range, but I haven't tried any that come close to the Siberas when it comes to comfort.
 
Over to music:
Gaming sound is a lot about high dynamic range, and with music I think the phones show their weakness at the other end. As the soundspace fills up the soundstage and separation go away. So, in my opinion they are not really for big rock and pop productions or for metal, hard electronica and other loud genres in general.
 
But, I think they really shine with more intimate recordings. The kind where you want a room rather than a stage. Vocals and acoustic instruments benefit from the mids and warmth in the lower end. Regina Spektor and Natalie Merchant sound as good as Leonard Cohen and Tom Waits. For club/electronic music I've enjoyed listening to chill/trip stuff like Air, Massive Attack and Portishead, and I think the bass works really well without taking over too much. Not much of a jazz or classical guy, but from what I've listened to I'd say small sessions and chamber music/solo/quartet performances work fine as well.
 
Some sort of conclusion:
I've talked a lot about mids and bottom, and those are the strong points to me. I'd say the sound is crisp with a dark sweetness. Honey roasted, maybe? The treble could be little stronger, but there are no real flaws there to my ears.
 
I haven't tried the phones with a proper amp, and as I feel they get muddier with portable devices and enjoyable with half decent sound cards and regular hifi headphone outputs it could be that a little more power could help keep those 50mm drivers in check even with louder music.
 
I've written this with the price in mind, and I think they are a bargain that rivals more expensive phones in the areas where they shine. With the retractable mic they make a practical and affordable all-in-one solution for all desktop needs like gaming, casual music listening and Skype calls.

Compared to the siblings:
This is the Promedia version of Klipsch Image S4 (and their S4i iPhone counterpart). Besides the gamer-friendly red and black coloring they also differ from the S4i by having a single button mic rather than the 3-button Apple remote. They also come with a Y-adapter that splits the TRRS plug into separate plugs for PC headphone and mic connectors. Finally there's also the standard three sizes of single flange tips, one set of small dual flanges, a shirt clip and a zippered pouch to hold it all.
 
Design and build:
Overall design and build quality is fairly good. The housings feel solid and have a nice finish, and the tips sit firmly on the nozzles. The tips themselves are well molded and have a line for proper alignment.
 
When it comes to the cables I have to admit that my feelings are mixed. They are ,on one hand, of a soft, rubbery quality that both makes them easy to handle and gives them very good microphonic properties towards fabrics. On the other hand, they don't feel very strong, and there's also a bit of elasticity that could make it hard to feel snags before it's too late.
 
The microphone is placed at chin level on the right cable, and its small size make these a more compact option for use with phones that can't use the three button remote*. Seems to do its job well, but considering the high placement I personally think the remote button would have been better placed at the bottom of the bulb.
 
Sound:
I think there has been plenty of discussion of the sound of the S4s, and I think my personal experience goes with the general opinion. The audio quality is about what I'd expect of something in the price range – they don't shine in any particular area, but there's nothing really annoying either.
 
They are a bit heavy on the bass, and there's something about that bass that is very average. A bit too weak for a heavy thump and still too tight to give a warm bottom to acoustic and other more open productions. But, looking at it from the Promedia angle, I'd say it does its job well in games.
 
There's also a bit of a weakness in the upper ends, and I'd say it starts at the point where they meet the mids. Female vocals can sound somewhat dulled, and so on.
 
Conclusion:
Overall, I'd say this is a fairly good deal if the intended use does include communications. The sound is, as the title says, competent but average and does about equally well with most types of music – good enough for the selection on the smartphone during commutes. They are also a good option for PC use for those who prefer IEMs and want something with a microphone for multiplayer gaming and VOIP.
 
 
*Keep in mind that plenty of Nokia, Sony Ericsson and Samsung phones have 3.5mm headset jacks that are wired in a way that requires an adapter to work with this and other headsets that follow the standard used by, for example, Apple and HTC. I don't mind the adapter as it adds a bit of protection for jacks and plugs, and although I've seen adapters included with a few headsets I still feel that the fact that the situation with two types of 3.5mm jack seems a bit overlooked.