I don't know, I kinda think Citrix is pretty fantastic. I don't find that end users have a problem understanding it. They just double-click the icon on the desktop and the application runs (of course it is being run on a remote machine, but they can't tell the difference).
The State of Utah uses it for it's vital records database, so any health department in the state that has internet access can connect and run Oliver (the application for recording and printing birth certificate's and such) over a secure, encrypted, connection. Seems to work like a champ. Extraordinarily fast, even though there are dozens, perhaps hundreds of people logged into it simultaneously throughout the state. Much faster than a web-based application would be. It also gives two-way access, so when someone is logged in, administrators can gain PC Anywhere-like capabilities with the end-user which is very useful for troubleshooting.