I have tried restoring my ipad multiple times over the last 2 days - each time it takes from 6-10 hours, and still nothing works at the end. What the f---?

A clean restore, or a restore from backup? If the second, try the first.

And what are the symptoms? Won't turn on, crashes a lot, ?

Otherwise it sounds like you might want to give Apple a call. If it's an iPad 2 it should still be under hardware warrantee, and it that's the problem Apple will fixe or replace it.

Thanks iPad wizard;eventually it all has come back, after many many attempts. Hopefully there won't be the same 'lose your app' problems with this new os. Happy Holidays.

Glad you got it fixed.

Most future updates for iOS 5 will be delta updates (small patches) that can be done without the computer; so it should be safer. Though it is always a good idea to let the bleeding edge upgraders do a bit of bleeding first; if you're not into risk taking yourself.