It looks great. I was playing around with something very much like this yesterday.... Never got it this good, though. I'd agree with Brent's comment that the perspective looks a bit odd; the table that the glass is sitting on must be about a meter and a half tall -- most tables are only about a meter high.... Further, the background plate (photo) is a little off square -- it tilts top to the left a bit; you can square that up in photoshop or any number of programs. It looks like the black levels in the plate are a bit higher than in the foreground. I'd check the ambient lighting level.... I'd wrap the backdrop plate into the background, too. You probably will need to tile it twice, but it'll provide info for reflections on the glass surface. One last trick would be to run the whole photo through a grain filter to add an even grain over the entire thing; give foreground and background an even distribution of grain.... Hope I haven't gone on too long.... Very cool job!