I have a friend who has a Beige version of that RS/6000 workstation, I think it's a 300MHz too.
I have a 7046 B50 2U server here, and while the hardware it pretty awesome (604e/375, 512MB RAM, 2x 9GB, and built like Fort Knox), I've never been a fan of IBM's approach to software. I used AIX 4.3...