Patches are 100% reliable if you do it correctly. You MUST scuff the entire area up where the patch is going to be applied. You MUST apply a reasonably thin layer of glue to the tube and you MUST let it dry for a few minutes per the directions on the patch kit. A properly done patch will last indefinitely if my multi-year old tubes are any indication. I used to carry no tube at all until I ran into a tiny steel shard I could not find and got flat after flat until my patch kit was used up in one ride. THAT was frustrating. Now I carry a kit and a new tube.