Vassal is great because it gives you access to ALL the minis produced, even if your physical collection is not complete. Plus, it allows people all over the world to play each other!
As for what I like to play, I put both. It's great for booster games (sealed), as shown by the Booster League that's been going on. However, I also like playing constructed games as well. Some people get upset at the dice generators, and yes I've seen them poop out on people including myself, but regular dice are just as fickle. ;)
PS: what's great about playing boosters is you don't have to go out and spend the money to throw together a sealed tourney. You can all just jump on Vassal, open random boosters on BlooMilk or Mini Manager and away you go! It's free.
