alt Hacker NewsI really liked XP (and 7) because for me, having a capable theming engine built in that didn't take a ton of extra resources or cause instability (unlike Stardock's WindowBlinds) was a real value add. There were some absolutely gorgeous third party XP/Vista/7 themes on sites like DeviantArt that worked extremely well within the limits of the engine, had a unique look and feel, and were just as usable as the "classic" theme.
When MS gutted the theming engine with the release of Windows 8 (flat rectangles only) I was devastated.
The 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.