my experience has been hit and miss with them. the first time I needed them, they were garbage, i would clean the tube perfectly and make sure they are well sealed etc... and 5 minutes down the trail "psssssss!" they blew again, and you could see a tiny line of where the air started escaping. they just seemed to not have enough adhesive. i used 5 or 6 patches on 1 2 hour ride.
I was too lazy to replace the kit so a few months later I got another flat (new tube). I repaired it the same way with the same kit, no problemo. It kept air so well that I forgot about it until I got another flat several weeks later. This one was right next to the seam of the tube, these patches didn't help much with that
I finally got a standard glue patch kit, and haven't needed it yet so I don't have any info on them. In conclusion, the glueless kits (to me) are very quick/easy/convienient, and they are thinner so you can pack several patches in a much smaller space than glued ones, but their performance is iffy. I think they would be fine for easy rides close to town where if your patches fail its just a quick walk or cell phone call for help. I would not recommend them for an epic wilderness ride where there is no cell signal and your bike is your only transportation back to the civilized world.
Oh i should add, my glueless patches were the thin clear ones, I've also seen ones that are the thicker black/orange ones that may work better.