vSCG or ZoneDirector?

[Mikhail]

I cannot find a comparison chart between vSCG and ZD, whats the difference?
And which one is better for small-scale deployment (1 Controller + 10 R500 APs)?

ZD1205 is a bit cheaper, on the other hand vSCG looks more reliable, because it can be deployed on VMware HA-cluster whitout addition expenses. But I am worry about features lacking in SCG (AD Authentication etc).