Keeping an OpenVZ VPS running smoothly requires a lot more SysAdmin attention than keeping a Xen VPS running smoothly. The Johncompanies people, last time I tried them, were excellent.
OpenVZ is a thinner virtualization layer. everyone shares the same kernel. It's resource separation isn't nearly as strong. On the other hand, it is also more efficient. you can reasonably expect to get more total performance out of a OpenVZ system than the same system running xen, but the problem is with OpenVZ, if one user is hogging resources, that user is much more likely to effect other customers than they would be under Xen, with it's non-shared ram and stronger CPU scheduling.
Also, thanks in general for your HN participation and frank and open discussion of your hosting business. I find it really interesting and also helpful the way you classify different types of hosting needs and potential good hosting fits, ( that are not always your own company ;D ). Very cool!
I'm reasonably familiar with OpenVZ and other "container" approaches (zones, jails).
It sounds like there's a missing abstraction layer, or maybe just fewer administrative tools for these container approaches than the built-in-at-time-of-creation attributes of a true virtualized guest.
