Since I've been using Gatorskins, I have not had any road flats caused by punctures. I have had flats caused by tube failures around the valve stem that can't be repaired. My wife, on the other hand, has had numerous flats on her trike and I do patch those using the pre-glued patches.

I scrape the area with the sandpaper provided, heat the area with a hair dryer then apply the patch while the tube is still hot. I press down on the patch for about a minute then heat the patch with the hair dryer while pressing down on the patch. Since I've been using the hair dryer to patch tires, I haven't had any pre-glued patches fail to hold air using this method. If the hole is close to a seam and the patch has to go over the seam, I throw the tube away.