I believe that's a mud flat in a river.
Seriously, alleging that there are aircraft superior to a Super Cub when it comes to overall STOL performance is an unwise occupation. You end up very quickly with a swarm of irate, rednecked Super Cub pilots on your tail.
QDM
J3 is much nicer to fly - more direct controls, far more chuckable and no silly flaps to worry about
Kingy,
The PA18-150 needs flaps. It's a lot heavier than a J3 and they improve the performance dramatically in all respects.