Personally I find XP really awkward to use now, largely due to the fact that the search box isn't there. If I want to load something like Remote Desktop, I can just hit windows key then type mstsc and hit return - so much faster. I use it not only as a search box for start menu files, but as a run box too.
I'm personally glad that MS have removed the classic start menu. The only reason people still use it is because they haven't bothered to take the time to get used to the 'new' style, which let's face it, is now basically 8 years old. I realise people are going to moan at this statement, saying that MS have removed user choice and are forcing users etc but if that's such a problem, why even bother to move away from XP? Keep the old OS with the old GUI if it works so well for you.
Besides, with a bit of playing around you can get the 7 start menu to work similarly to classic start anyway. One example I saw was to rename the 'Downloads' group on the start menu to something like 'Programs' and then change the target location to the start menu path. Sure it's not ideal but the programs menu works virtually the same then, except you also get the added functionality from the rest of the start menu.
Personally I hated the XP and Vista start menus when I first started using them. Now I find it hard to go back.