Dude, this is some really nice production. I'll be straight up, I wouldn't buy this if I heard it in a shop, but I would probably bounce my head plenty if I heard it out.
I can't really fault any part of it either. The drums are done really cleanly, they remind me a lot of Train Version by Calibre on that Creative Source EP a while back. The vocal is treated nicely, in fact the delays & reverbs are really well programmed and mixed throughout the tune. The pads are pretty good, nice thick texture without occupying too much of the mix, and the sounds all sit well together.
In fact, the only thing which I'm not keen on is the synth bassline (not the sub), but that's only because it sounds less refined or well designed a sound than the rest of the tune, and that's more a matter of taste than anything else. It's not quite the sound I'm into D'n'B-wise, but it's as well produced as most stuff in the same vein that I hear in the shop/round my mates' houses/in da club. Job's a goodun.