I have pretty much the same setup as Darrin, without the FastATA4000, Deneb, Spider and SB128....Okay, not really the same... but I use the monitor/indivision the same way.
The problems I have run into were with lockups in Radeon resolutions. Higher resolution, the quicker it locks up. I think my problem is one of the programs I am running. Once I disabled AmiDock and the memory info program, it locks up less.. Still haven't figured that one out, but it may be a bug in ClassicWB.
Otherwise the video modes are really fast, and if it weren't for the stock 040 and the slow IDE drive, it would feel snappier than Windows 7 does on my system with 8 cores and 8 GB of memory!
slaapliedje
When I first bought my Amiga+Mediator setup (used) I had the same lockups as u.
It all turned out that there was a jumper on the mediator for safe or dangerous. Well dangerous always crashes. Safe never crashes. STUPID JUMPER!
Once I changed the jumper over to safe. Everything was fine. And my transfer speeds dropped from 11MB/sec to 9MB/sec No prob since it made my Amiga rock solid for many years.