Greg, this is truly amazing... I can't think of it being your 1st or second attempt to ambient music, it sounds very professionnal in the production, and amazingly well composed.
I don't usually use that much superlatives to describe a tune, but this one is seriously impressive.
The only think I would have done differently is maybe the bass line... I don't find it very original... the idea of the sine bass is good, but the way the pattern is constructed sounded pretty simple to me... I'd have used some more envelope on the bass notes to make them fade out... that's really nit picking man!!!
overall, some amazing stuff... I'd doubt that Di.Fm wouldn't want it, seriously.
Congratz!