The only question is WHY?

time ps -aux in XEN:
real 0m0.024s
user 0m0.007s
sys 0m0.003s

time ps -aux in KVM:
real 0m0.008s
user 0m0.003s
sys 0m0.000s

Hopeless...

I would suspect “WHY” is because there is literally no room left in the Tokyo datacentre for new hosts. KVM Linodes require entirely new hosts, and they'll need to start with enough of them available to handle the initial flood of converted guests. If they had spare room in Tokyo for an array of KVM hosts there wouldn't be the current shortage of openings for Tokyo Linodes, and thus KVM in Tokyo will wait until they open up a new datacentre.

Thanks. But we'e heard that for a whole year. I doubt if there is an expansion in scheduled.

You doubt that Linode is planning to expand in their most hotly-demanded (and therefore highly profitable) region?

I certainly don't think Linode fails to grasp the economics of that situation — but I do think that Tokyo is so densely populated already that it's hard to find space for the capacity they need, for a price they can afford. Expansion in Tokyo is inevitable, it's just not quick.