Patches rule. I just repatched 5 tubes this past weekend.

I do admit that even though none have failed for me, I get a bit paranoid about it, and what I ended up doing is actually removing the nonpatched tires from my bike and replacing them with the patched ones. That way, if I do flat on the road, there will be no question about patch failure.

Again, have never had a patch fail yet though, and I've patched about 15 tubes thus far in the past few years. However, I HAVE had 2 patches which were not placed on correctly, meaning I basically missed the hole, or only partially covered a linear larger tear, allowing air to leak from the free edge. That's what I'm really worried about - my own user error, as opposed to patch failure over a well covered hole.