alt Hacker NewsThe engine itself isn’t gutted - it’s full of functionality that was never lost. MS just (correctly) reasoned that transparency effects in the UI - introduced in Vista simply to show-off the capabilities of the DWM compositor - ultimately detract from a good UI.
From what I remember it lost the ability to render rounded window corners, because while Windows 8 msstyle themes existed they all had the hideous boxed corners that clashed hard with many looks.
I don’t agree that transparency is always a detractor. Judicious use can be a net positive, but it doesn’t work for all themes and there should be an option to turn it off. Personally I didn’t find the W7 variation of Aero to be bad at all.