I kind of agree with you. I have a 2002 C230 with absolutely no optional equipment other than auto tranny, and I think it's great on so many levels. No complaints from me.
However, the changes made to the 2005 C class are an improvement. First off, the CD player that's standard is well overdue. I like the new gauge cluster and the aluminum trim, as well as the redesigned cupholder. But none of it is "vastly superior" to the old style. It's just different, not necessarily better.
As far as exterior styling goes, I've only seen the C230 sedan. It looks very much like a C32 from the front. The changes are very minor, but it does enhance the sportiness of the car. Not a lot, just enough. Honestly, unless you know what to look for it's hard to see any difference. Personally I also like the 5 spoke aluminum wheels over the 7 spoke ones with all the little bolt-heads around the rim. It looks less "messy", but again that's just my opinion.
All in all, the changes to the exterior are slight but enough to enhance the look a little. The interior is more noticable, but not necessarily better - just different. My wife likes the old style better, I like the new.