I find FG2 to be an excellent way of playing DnD. If I ever start another live group again, I'll definitely be using it. It's an amazingly versatile piece of software. It was designed as a "pure" tabletop simulation, low in functionality, but designed to completely recreate the tabletop experience. But with the robust scripting system (using Lua), there are nearly unlimited possibilities. Eh, starting to sound like a commercial now.
Specifically, I've found that my groups run combat much faster in FG2. Also, because most people are more willing to RP in chat than act things out in-character at a table, the RP is on a different level from just playing at a table.
However, there are a few "cons." I know some of my players are annoyed by the level of automation we use. It's completely optional, but I'm a huge fan of automation, so there's a potential to alienate players one way or the other. Also, FG2 does have the occasional issue. The community is very friendly and will quickly help you figure out why you're having problems, but it's still one of those things that just don't happen at a table. Nothing sucks than having your game interrupted but a crash. If I were you, I'd do some research on the forums to find some of the common issues that only experiences players know that aren't documented anywhere.