I also grabbed a pair of H15's from NCIX just to try. I didn't really have high hopes, I wasn't sure how comfortable they would be. The impression below is based on the $100 purchase price.
After living with them for a few days I have to say I'm quite impressed. They aren't flat by any means, they have a full bottom end, and tame but fun mids/highs. They aren't anywhere near as revealing as the T1's, and after switching from the T1 to the H15 there is a noticeable veil, but I have to say they can be more engaging and fun to listen to. I think they got the right balance of detail and fullness in a lower cost headphone that will give you an enjoyable listening experience without the feeling that you are missing something. They are very easy to drive, and I found the best combo was simply an Iphone 5 driving them directly. I don't have a single ended portable amp to test them with at the moment but will try something soon. Certain aspects improve with a desktop amp, cleaning up the low end a bit but not to the extent I would say it's required to enjoy them. Given the listening experience (and the fact it comes with an Iphone remote cable) I would have to guess they were designed/tuned/refined with an Iphone and/or current ipod and that's how I would suggest listening to them. They work well with a 6th gen ipod classic, but doesn't quite have the synergy of the Iphone, in the case of the classic, I prefer the H15's amped which gets them closer to the toe tapping fun of the Iphone with an extra level of clarity and refinement from the amp (this doesn't make it better than just the Iphone + H15 though).
Build quality, at $100 I would say they are very well built, given the normal price of $200 I would say they are on par with what I would expect at that price point, not exceptional but not lacking either. The accessories and travel bag are nothing special but nice they are included. They aren't the most compact, but they are quite light and easy to manage, folding flat makes them a bit easier to store.
Finally comfort, this was my biggest hesitation when looking at these, however the very soft pads and ample headband cushion make them quite comfortable. I wear these a bit high and forward so that the lower portion of the headphone pad doesn't press on my jaw, and fit like this I find them very comfortable even for hours of listening. I typically wear glasses and a hat and the H15's fit well with either/both of these. The other surprise is that they are very non-fatiguing even at fairly high listening levels making it desirable to listen for long periods.
In conclusion these are far from a reference headphone, but for me they fill the portable need in a very enjoyable and fun way. It's very easy to just get lost in the music and just enjoy it. These have replaced my MS1's as my favourite low cost on ear headphone. Either this new generation of $100-200 headphones is better than they have been in the past or these Paradigm's aren't getting the recognition they deserve, but in all fairness I haven't tried all of the competition yet.
