I'm interested as well. See my other thread about rsync here. This kernel is surprisingly slow in some specific workloads. I know this is completely unsupported and untested (by PVE devs), but would it be possible to run PVE with an Ubuntu or a Debian kernel? Losing OVZ capability, of course.
So am i.
I wish it would be optional to install Pve with a modern kernel if you like me dont care about ovz.
I also have tested modern fedora and ubuntu distros vs. latest pve, gaining better performance and significant reduction in power consumption on i7* sandy bridge and ssd hybrid's.