This might sound like a silly topic, but it's infuriating.
It's only very recently (since July) that I've adopted the Ctrl-Alt-Arrow Virtual Desktop bindings. Call me an old todger, but up until now, I've always remapped Alt-F1 through Alt-F6 as my Virtual Desktop keys. That's how I always switched desktop, and I couldn't bring myself to change to the Ctrl-Alt style.
I try to slowly align myself with the new defaults, so that I have to do less customisation to feel comfortable when I sit down at a box. With the MacBook which infuriatingly requires Fn+ for the F-keys, I thought I'd switch. It took a bit of re-training to switch, and now I'm comfortable. But, every now an then, I accidentally press Ctrl-Alt-Backspace and kill X. This combination is supposed to be highly unlikely to be accidental, and used to be. But with the default gnome bindings, it's quite common. You just finish editing some text, and switch desktop, to find that your right hand hadn't fully released the backspace key before the Ctrl+Alt went down.
I think either the X kill key needs to be changed, or we have to get rid of this silly gnome desktop-switching binding.
OTOH, I'm almost entirely in line with the modern GNOME defaults. On a foreign machine, I need to set up Dvorak keyboard, change the terminal to grey-on-black, and I'm pretty much ready to go. (My .ssh/config is also nice to have, as are my firefox quick links)