I start by myself :p
> - do you use 3.x kernels ?
> - if yes do you choosed 3.0, 3.1, 3.2 3.3 etc ?
3.2 because of cgroup blkio.throttling. I start to use 3.0 for some
where blkio is not needed
> - if yes have you met any issues ?
yes main line issue not related to vserver is seems with process locked
in D state and kernel panics. I hope 3.2.14 will solve this :)