I have a XenApp 6.5 farm of around 30 servers running on Server 2008 delivering a published desktop.
A fair percentage of our help desk calls are around hung sessions. It's not an excessive amount for life with Citrix I don't think. I recently discovered that a lot of these calls were not actually XenApp session issues but crashed applications, the kind everyone is used to with MS Office and the like, that you would normally just end the task for.
We currently deny access to task manager with a GPO. I think this was done for fear of users logging each other off or killing processes of others. Having tested this myself that doesn't appear to be the case, can't view other processes or log off users. You can create new tasks, but other security settings should prevent any issues arising for us from that.
I've seen a few 3rd party task managers which are made for Citrix, I did try Task Nanny briefly. It seemed useless to me as obviously it's not integrated with the OS and couldn't be launched when it was actually needed. Why do they exist? Filling a gap which no longer exists?
My question really is do you give your Citrix users access to task manager? If you don't, why not?