Apart from the technical limitations, what seriously fucks me off about BIOS is how every manufacturer has a different standard for everything.
Some use F2 to enter the Setup menu, others use Del, others use Esc, others use some random key. Then the actual Setup options are spread across a mind-boggling array of menus and sub-menus, with very little consistency. Menu items often have no description, even in the included documentation.
Also, some BIOSes are just plain buggy: some don't correctly save boot order, some advertise F12 for network boot but it doesn't work, etc.
Is EFI going to solve any of THESE problems?
I doubt it.