I just finished using Fog Creek’s Copilot for the first time with a Felix user, and I must say that I’m impressed.
Using Copilot, I was able to remotely control the user’s desktop from my own computer. In a few minutes, I was able to run through most of the possible issues, eventually finding the problem (the user had been using an older version of Felix, and the Felix interface for Word had apparently crashed, because Word had disabled the Felix add-in).
From experience with other users, running through the kind of checklist I just completed using email or the telephone would have been extremely difficult, if possible at all. Copilot made it very easy to get in, find the problem, fix it, and get out while the user went for coffee. Very nice!