I have both a Mediator 4000Di and an Indivision AGA. Doesn't seem to cause any major heat issues that I've noticed. Then again, I haven't actually put my hand between the the two while it was turned on. Could possibly explain my lockups while using the internet though.
It's kind of odd though, I would browse the net with the Aweb version that comes with OS3.9, and then it'd start to lock the system after a short while of browsing some sites. Then I'd switch to ibrowse, it'd work for a while. Then it too would start crashing the system. So then I would use the Aweb_APL_040 I had laying around my hard drive, and it too would do the same thing.
Then I updated my Mediator drivers to the newest. Odd thing is, I swear the card I bought from Elbox was a 64MB card, and I had manually added the extra ram to Fast RAM. But then when I updated the drivers... suddenly I have 100MB of Fast RAM instead of the 55MB I had before. Awesome, free major upgrade!
Otherwise my fairly stock A4000 (040 with 16mb of ram and above addons) is very fast for a 15+ year old processor!
I haven't bought a Deneb yet, still trying to think of a very good reason to spend the cash on it.
slaapliedje