I've had no problems with Lezyne self-sticking patches. The kit is excellent for a minimalist seat bag -- it's a flat envelope, about half the size of a credit card, with several self-stick patches, a metal roughener, and instructions on a sheet of plastic that doubles as a tire boot. Used 'em several times on my hybrids and road bikes, no problems that weren't due to operator error.
As other folks noted, it's essential to rough up the tube wherever the patch will make contact. The mold release agent needs to be scrubbed off. Takes a little more effort with the metal scrapers rather than sandpaper.
I still use regular patches and glue at home, but I don't carry 'em with me on rides. Just the self-sticking patches, spare tube(s), etc. Usually I'll try to patch first before swapping tubes, because I try to patch without completely removing the tube. Makes it a little quicker, unless it's a tricky flat.