I tried moving us to a TS environment about 4 years ago - I couldn't get past the thin clients 'flashing' on websites that used Adobe Flash. When moving between screens on our EMR of the time the whole window would flash white before going to the next screen. I posted about it on SW... someone posted a reason why (can't recall now). Never had the problem when using a Windows machine as a terminal into the TS.
In the end it worked out since our current EMR strictly forbids TS.