I ran a PLUS league last year (in addition to maxing out on free leagues).
A couple cool options that make life easier on commissioners:
- Ability to place all available players on waivers Sunday through Tuesday (avoiding the Sunday free-for-all). I got tired of locking/unlocking everyone on game days.
- You can edit the point total for any team on any given week of the season. Doesn't seem like much, but seems like once a season (at least) something happens to necessitate changing someone's score manually.
- Division play.
- Let's see -- you can also do bonus points for in-game milestones like 100 yards rush/rec., 300 yards passing, whatever. Might be kinda a niche thing but a cool option if your league likes it.
And of course there is StatTracker. Everyone is probably going to buy it anyway, so if you add that up x 10, 12 teams, the extra features are probably worth it for the few extra bucks.
Checking out their help site, looks like the remaining features are research/data related.