I've been buss-powering my 26 i/o with my MBP . . . unless I just imagined those recordings! Not so much of a problem with glitches, but the SaffireControl software is a POS and occasionally turns phantom on/off at will.
Not tried it with Leopard yet, didn't think there's be a problem but now I'm worried . . .
I've been using it full time for a couple a week and returned it. The clock is more than bad. I've never been able tu sync it properly with a DM2000 and Logic had some very strange behave... I don't recommend it. If you want the sound (as a master) with the pre I would recommend the 10 i/o, it's little sister. It's cheap and the feature in it work. Not the 26 i/o.