Yeah, I've had a look at the few circuits that are doing the rounds and it looks like it does switch to 16MHz only when the bus isn't being accessed, rather than being set to 16 all the time - if it was that easy, Atari would've done in the first place, would they not? I've heard all sorts of problems like the keyboard and MIDI ports locking up if ran at 16MHz. Apparently it was quite common for Amiga users to swap out their 68000 for an '010 but I've not really come across it in the Atari world.
Anyway, take a look at www.fatrakoon.co.uk and see what you think.
