Qdm,
The PA18-150 needs flaps. It's a lot heavier than a J3 and they improve the performance dramatically in all respects
Sorry mate disagree with this, they don't really lower the stall speed much do they, what 2-3mph on the second stage? They add a lot of drag though and make it easier to see over the hose.
Cubs are just about the best slipping machines ever invented - give me variable drag I can throw away in an instant any day over drag flaps. Of course you could slip a PA18 as well as using the flaps, but most Super Cub fliers seem not to...
Also on the STOL thing, Super Cubs are not the last word. I've seen a Yak 12 in action - almost unbelievable STOL performance. I'm talking a few feet take off roll - makes my L4 and probably your PA18 look like like an overloaded PA28 on a hot day! Damn it
Kingy
PS come and have a go in my Cub if you've not flown a L4.