Well, Firefox works well under 7, apart from wacky things with font size (visible above).
There isn't a boot.ini in the version I have. It's all done with BCDEDIT, and that tells me I don't have the rights to play with the BCD. That's the only place it's played the "Admin" game, which is a major improvement on Vista.
I'm about to dig out my Knoppix disk, to reinstall Grub and the menu.lst approach to multi-boot. That's a lot more flexible (and easier to drive) than a BCD that won't talk to me anyway
Now if I can just get this pesky Network thing to accle...