What is the problem with UEFI? I have only installed Linux on a few computers with UEFI so far, so I don't have a great sample, but I haven't seen any problems. (I have heard about secure boot that cannot be turned off - how often is this the case?)

It's annoying. But for the end user the install is just a button and a minute more. At least on Linux.

I've yet to own a UEFI motherboard without a few glitches. I never had these problems with the BIOS...

I had. For example, HP EliteBook 8470p claims the drive is not bootable if there is a DOS partition table where no partition is marked bootable (I think it shouldn't parse the partition table at all, just check the magic and execute the first sector).

What glitches have you seen (so I'm prepared when I meet them)?