As far as the controller itself, I didn't notice any structural difference between this controller and my old white controller that came with my Pro 20GB Xbox 360 several years ago. I did notice, however, that this controller properly charges my Play & Charge Kit where my old one did not. Prior to buying this controller, my Play & Charge kit would always show the red light while recharging. Since the recharging appeared to work anyway, I didn't think much of it (especially after calling Microsoft and being informed that the warranty on accessories is only 90 days, though that was in 2008). Since I assumed that the battery was at fault the whole time, I was surprised to find out that this controller charged the battery and (correctly) showed a green light when charging was complete.
Though it did not appear to be a structural change to the controller, I had somewhat forgotten (or not realized?) how much wear my controller has taken over the four years (give or take) since I got my console. The new controller gives me a bit more precision in games, especially with the right stick and the pushing of the sticks (for activities like sprinting). The tactility of the sticks (with little raised lines for grip) were a nice reminder of what my controller seemed to have at one time.
This was a satisfying purchase for functionality and the nice sleek look of black. I should also note that while the description of the item is "Glossy Black," this controller isn't really what I would call glossy like you would call the bezel of an LCD monitor or clear coat on a car. It gives off very little gloss in my opinion, which is fine by me.