I can't say anything about 5 but 4.5.2 runs GREAT on my setup. I run it on a Slackware box (check my sig) and it hosts Slackware, FreeBSD, XP, Solaris and am working on hacking my install disks for AT&T SVR4 2.1a to install in it - never had any virtualization software able to install this one). If the only virtualization software you've used is Virtual PC, you will be very pleasantly surprised. I imagine 5.0 is even better. About the only thing that I wouldnt try to do in VMWare is (of course) heavy gaming.
Wine can also work in many cases if you are mainly trying to run Office programs and tools, with a lot less overhead than emulating an entire box. (
http://www.winehq.org )
--Scott
PS: does anyone have any experience with the later versions of Bochs? especially Solaris 8/9/10 and SVR4 2.1a(i386)?