We don't use jacks,,, probably because our little Sunseeker does not have any !!!
But when we had a TT we always used them !!! Also it had a Super Slide !!!
I have an 18-foot Micro Lite and quit using the jacks a couple of years ago. Just wasn't worth the trouble for the hardly noticeable difference in stability. We also have a 29-foot bunkhouse and do use the jacks with it because, with a slide, I feel it needs the added support.