Depends on what kind of paintball you played.
If you played mostly woodsballs or scenario ball it's going to be a pretty easy transition. IF you played speedball you entering a whole new world.
Depending on what airsoft game you go to expect anything from a slightly more realistic experience than woodsball to an imersive milsim environment. either way airsoft is allot more honor based.
Since I switched from woodsball i haven't played since. If a friend was organizing a paintball day I might go but for my personal preference it's 100% airsoft now.