On a Beta 001/LE system, the answer to your questions is 1 & 2: yes the default rate is 48K. You also have a 44.1 option, and can switch the hardware to play back any session at either rate - although I am unsure why one would want to play back a 44.1 session @ 48. re: question 3 track performance on the 2 sampling rates. I haven't had the chance to compare. The only 44.1 stuff I've done is conversions after bounce to disc mixes for CD burning. A 400 G4 Yikes with 250 MB ram and the supplied MAC drive handles 24 tracks @ 48 K no problem, with processing as discussed in previous posts. I plan on adding a second ATA or firewire drive soon and dedicate it to audio recording. Hope this helps.