Time to add in my two cents...
Actually, I found them very sensitive to sources as well. I don't have amps so I can't really vouch for how they will react under different amps, but you can verify the sheer difference on sources alone, say a Sony Walkman vs. Sansa Clip vs. iPads. There are distinct difference coming from such sources, and for the most part, I think these have been colored (optimized, ahem) to match iDevices. I got the best results out of iPad2 (64GB, AT&T GSM if anyone cares). From other, slightly more neutral (?, at least non-Apple sources), I couldn't really use these too much because of the mid-bass hump. Everything else was just dandy, but the mid-bass hump just killed it for me. That was until I blocked the bass ports on the stems. Both of them (not the ports on the driver housings).
If anyone's really bothered by the severe (and to me, they were severe) mid-bass hump, try taping off those two ports with a bit of scotch tape. Holy crap! Now the bass has body and volume without the fatiguing flab. The soundstaging on these are quite nice as well, probably on the level of MDR-E888 (remember those?). They are about the only earbuds I can recall that has a very open soundstage. The Earpods are easily a match for the E888s.
The hard plastic housing bothers the ears a bit. But then again, it's kinda like Triple.FIs in that respect. Otherwise, they stay in the ears quite well and just disappears. I know they are still there, but not as obtrusive as other IEMS.
Overall, for $30 and couple of pieces of scotch tape? Not bad at all!