So far, all the problems I've had with 2.0RC5 are pretty minor:

1) the sleepy mesh drive on my PowerMac 7300
mesh0 at obio0 offset 0x18000 irq 13: 50MHz, SCSI ID 7
scsibus2 at mesh0: 8 targets, 8 luns per target
sd1 at scsibus2 target 1 lun 0: <IBM, DCAS-32160, S65A> disk fixed
sd1: drive offline

2) sysinst doesn't offer DHCP network configuration!

3) /dev mfs doesn't have enough inodes if /dev isn't populated

4) when mc0 is unplugged (on PowerMac 7300) and unused I still get a 
bunch of errors
Nov 14 14:49:25 al /netbsd: mc0: collision error
Nov 14 14:49:25 al /netbsd: mc0: lost carrier

5) Can't get VLC to work (thread issue?)

As for stability, I've built 400 MB of binary packages and had 
approximately zero problems related to macppc.  Of course my PowerBook 
also has 640 MB RAM so some of the low memory problems you're talking 
about don't happen to me.  Also, neither machine I own has grackle.

   -- MW