I have seen zero problems mounting my portable VST 12GB drive (firmware v56) and my AC powered Oxford911 bridge based case kit drive with onboard IDE formatted IBM 75GXP 60GB drive (the one used in my review and build guide posted here on the Firewire articles page.) used with my G4/500 DP system running 10.1. No problems with them after waking from sleep either. (I repeated these tests over half a dozen times.) The drives were still mounted and usable.
So 3 years ago on a very early version of OS X firewire worked better?