Haven't had the pleasure of trying it yet (I haven't moved to BR yet,) but I've read 59% CQ for HD rips. It'll be good to see what dynaflash says, though.
tbh, I haven't done alot of blu ray rips ... only some light testing. 59% would seem plenty and with decent opts 25 - 27% should look awfully nice going to the atv's 720p. Cave, I believe you've done more testing than me