Found my EP-630 waiting for me at my doorstep this morning.

All excited, I did the necessary checks, got my ready-waiting MP3 player and plugged it in to test out what all the fuss was about. I sat quietly, and took my time to listen to the various genres, namely vocal, techno, eurobeat, jazz and pop. All shared something in common:
The mids to highs were severely lacking.
The bass wasn't all tight, but definitely more agreeable over my previous earphones, a Sony MDR-E801 (don't bother looking, I got it bundled with my 10 year plus Cassette Walkman and I can't find any info for them at all). I was quite disappointed when the mids and highs in comparison with the E801,
were almost the same. You could imagine my dismay that my early 1990s earphones performing equally over my new EP-630. Comfort levels were definitely better, them Creatives being IEMs and the E801 being standard earphones. My ear cavity used to ache after a while with them, but now with the IEMs it's a little easier.
This most likely biased review came after a short test run with my friend's Sony MDR-EX85 earphones, yeah I know I shouldn't be comparing earphones of obviously different pricetags but you somehow, always try to believe that it sounds the same

Burning in the EP-630 for a 12 hour stretch, hopefully it'll perform better after a bout of warmup.

Earphones don't perform the best when you just got it.
Well, try to hear the difference after burning-in. Last time my stock EP-50 sounds so darn good after hours of using it, same applies to EP-630 too.