I too once was jonesing for a Sam440, and ended up buying one, but sold soon after as while it was fun, it was disappointing in some ways. I too am a UNIX guy, and I think this did not help matters.
Basically, I'm used to computers being reliable, in the case of Solaris, I've never seen a kernel panic in the wild, ever. The Sam on the other hand, very unreliable, if an app crashed, the OS was generally not long after crashing too.
This was the major problem, the second problem was although as you say, they're *very* quick to boot, for compiling stuff like C/C++, it's painfully slow, to the point that my productivity was affected, combine that with the unreliability, I soon ran back to my Mac.
It's purely a matter of opinion, but I find the GUI sound, decent, but not outstanding. I really like the Amiga screens system but the Sam440 does not have enough video memory to make it shine, so you'd be best with a Sam Flex and get a better video card.
I don't have much experience with NeXT, but some with BeOS, and I think BeOS has the nicer UI than Amiga, but again, purely opinion.
Just my 2 cents.
Garry
