1. It's usually not an overpair to the flop.
2. Trip jacks come as often as trips to any pocket pair.
3. Dies to overpairs

That means it's not nearly as strong as the "big" pairs

What's good about it:

1. Sometimes higher than your opponent's kicker
2. Blocks the straight so it's 57% against AK
3. Is sometimes a higher pair to someone else's smaller pair
4. Dominates AJ

All in all, it's a weird hand

I raised half my chips in a freeroll deciding to push it no matter what flop with jacks. I got three callers (wtf?) and one overcard on the flop. Pushed it on the flop after one guy minibet, lost to... trip sixes... the guy took forever to call my all-in with them too XD

Any better way to play them? The blinds are 1/10 of my chipstack anyway in the freerolls.