@Gazsp,
I've had an A3000D for a long time now, and just recently aquired an A4000D. FWIW, here's the opinions I formed of the two:
4000 pluses:
It has AGA (very nice).
It is roomier and seems to suffer less from heat problems than the 3000.
You only have to worry about the buster revision for Zorro III and shouldn't experience problems with expansion cards.
4000 minuses:
Many of the chips are soldered. The only socketed chip on mine is the buster. On some 4000's, even that is soldered along with chip ram.
Keyboard and mouse felt cheap (I'm not sure if they were the original ones).
It's a pain to disassemble.
3000 pluses:
Built-in SCSI.
Built-in flicker-fixer.
Nearly all the important chips (like CIA's) are socketed and easy to replace if they fail.
Low profile "slim" look about it.
3000 minuses:
No AGA.
Sometimes suffers from heat issues, especially if you put an accelerator in there.
VERY cramped inside.
It's also a pain to disassemble.
Depending on the revisions of buster, dmac, and ramsey, you might have problems with some expansion cards. Also, some expansion cards more than likely will NOT work properly no matter what you do (such as Fastlane Z3 --- my 4000 loves it, 3000 hates it).
At the moment they both have A3640's and 16MB of RAM. Except for the 4000 having AGA, I really do not see a difference between them when using them. They both feel about the same. I guess I'm still partial to the 3000, mostly because of the built-in SCSI and flicker-fixer. But either of them is a very nice machine to have.
-David
