I suspect you could have made Xen (on the high end) or Jails (on the low end) equally as powerful. I'm not a fan of Zones, and of all the Solaris innovations of the past couple years, I think Zones have the least staying power.
Yes, you have made your bias very clear on Zones here on HN every time the subject has come up. Clearly they don't work well for you. However, people do use Zones and they clearly do work well.
I suppose you have figured out how to use a jail to limit memory and CPU resources of the programs running in a jail? Ooops, that is a zone-only feature; like the time I set up Oracle in a zone and limited it to using no more than 4GB RAM .
On the high end, I'd use Xen, like all the major large-scale hosting providers do. On the low end, I wouldn't bother trying to do fine grained resource control.
It's not exactly insightful to point out my bias against Zones in a response to a comment where I basically say "I'm biased against Zones". I am indeed biased. And I can defend my argument that, as a technological approach, trying to compartmentalize all the kernel namespaces and building ad hoc group-level rlimits is a dead end.
For what it's worth, just as your bias in favor of Zones (which I don't fault you for) is based on professional experience, so too is my bias against them.
