That may be true for your configurations, but with the configuration I am running (dual Athlons) I have had nothing but trouble. With the very latest updates, Zope 2.6.2b3 now seems stable running under Python 2.2. I am still fighting problems with the Pound front-end which is stable under RH7.3 but non-functional under RH9. Incidentally, my installation was clean followed by multiple upgrades via RHN to apply all the latest updates.
I personally never had much luck with dual Athlon systems, so much so that I will refuse to buy them for any professional work. The same holds mostly true for self-built servers in general. I have extensive experience running very large Zope/ZEO deployments and would never buy anything but Intel-based servers from brand-name manufacturers anymore. jens