A client of mine experienced some slowness/freezing of XenDesktop 3.0 sessions when used from India. The slowness is experienced during logon, but also during a minimize/maximize of the XenDesktop session or during an unlock of the local PC. Here is the background of this issue and what was done to mitigate the issue.
Background: Client uses folder redirection of Application Data folder. That AppData folder is currently redirected across the WAN because of lack of infrastructure in India. Yes, I realize this is an extremely bad practice, but it's what they decided to do and it's what I currently have to deal with. Client PCs are in India. XenDesktop VMs are in Chicago. Circuit is 9MB bandwidth and approximately 270 ms of round trip latency.