2-hr massages, plus and minuses?
I enjoy doing 2-hour massages, but it helps if the client has some specific issues for me to focus on. If not, I use it as an opportunity to practice a wider variety of techniques than I might normally use in a 1 hour massage. I might get two, plus some shorter sessions, but it's rare for me to do more than one 2 hour massage in a shift.
The longest massage I have done was around 4-1/2 hours nonstop. It was a lot of fun, and I finally brought it to a close when I realized that my client probably couldn't handle any more. It was physically fatiguing, but the fun helped maintain my energy level throughout. However, I think 2 hours is probably a good maximum for most massage clients.