Yeah our online games here were pretty tight, especially messing with Laddy's system.

The problem is as on the table the preparation is tough, maybe harder to get what you imagine your digital tabletop to look like actually on the platform. Using chat also slows things down to turn a multi hour session into a one-encounter deal whereas you can usually get in a couple in real life. I feel like webcams would be a big help but I dont know how feasible it would be with 4-6 people and a platform thats probably still in beta. One slight advantage to online is that it's slightly easier to get people together since we're at our computers anyway but assembling and keeping a real life group can be daunting.

As far as systems I like the usual 3/3.5/pathfinder mash up supplemented with house rules. 4 is easier in that its more video gamish, but if you're a DM you now have to keep track of the dozens of abilities your party has and make sure they're using them right and understanding them. Fighters should swing swords and that's that.