However, I wouldn't say that MapTools is "very easy" to use. You will spend SOME time and effort trying to understand the interface and spend even more time to make full use of the application's capabilities. While that may not sound like a ringing endorsement, I found the energy and time very well-spent especially if one is determined to run a game online. There are also screen-cast tutorials out to help you along the learning curve.
I played in a few OpenRPG games a while back and that experience was OK. Over the past few years, I made several attempts to re-install the latest version(s) of OpenRPG and see if I could make a go of it but I always found the UI, the tools and all the XML stuff a bit daunting.
I was also encouraged to find an active and VERY supportive community on RPTools.net. One of the players, a veteran Savage Worlds DM and an RPTools regular, set up the campaign properties (e.g. stat block) and some basic scripts to help with the trait and skill rolls.
I found that I had to do a good amount of prep work setting up the tokens, embedding the stats and making maps. I spent a lot of time making maps but that's really not a necessity as there are a lot of good maps out there. I chose to make some custom maps and also re-scale some existing maps to the grid I was using. All this work saved a lot of effort and time during showtime. The players and I were able to focus on what was going on with the characters and their adventures rather than mucking around with the software.
MapTool does not support voice chat and I only used the MapTool's native chat last night. The chat interface saw us through the game just fine, if not a bit slowly. This is obviously a detriment especially if you or one of your players type slowly. If I were to run the game online again I would use voice chat (Skype conference call or Ventrillo, probably Skype since it's free).
For those interested in MapTool or other Virtual Gaming Table (VGT) software, check out this chart to see how each application stacks up against the others.
Does anyone have any experiences with MapTool or any other VGT software? It doesn't matter whether they are similar or contrary to my experience but I would like to hear your war stories. :)