I've so far run 4 sessions of my GURPS campaign in the past 3 weeks, and have announced that I'm taking a week or two off from running it so I can build up the framework a bit more. A two-hour combat with 20 participants was waaaaay too long, and there's too much "Oh you're attacking? Hit the 3d6 button," for my tastes. Running pretty well so far I think.
The main campaign page: http://cago.ranter.net
The MapTool posts: http://cago.ranter.net/category/maptool/
I'm logging my experiences with MapTool and building my framework (hampered by my relative lack of coding talent) to keep track of what I did, what mistakes I make, and how I fix them. If someone sees a way to improve things and make them easier, great. If someone can pick up something useful from my experiences, even better.
PS: Thanks to gmjasongurps for letting me lurk one of his Wandered Roads sessions. Much better use of the kit than I was using, gave me a lot of good ideas.