The Good: Sticks well, doesn't slide or leak. Lasts as long as a traditional patch. Fast and easy to apply.
The Bad: Only one size available (as far as I'm aware)
Everybody should have a package of these in their saddlebag or backpack. They're far faster than a traditional vulcanizing patch, and they last just as long. I have tried other brands of glueless patches with poor results (one brand almost left me stranded) but Park Tool's patches have never failed me. The box is tiny, and if you suffer multiple flats on the same ride, it could get you home. This patch kit is one of my essential items for any ride.