All of the catastrophic or near-catastrophic tire problems I and my family have had were on tires that were new or nearly new, meaning there was a manufacturing defect. For this reason, I'm not as confident in a tire until it gets through the first 250 miles without a problem. I would want to have that many miles on a tire before starting a tour on it. I've bought and maintained somewhere around 200 tires for myself and my family though, and we've never had a problem that could not be fixed with a boot. That even includes a full blow-out where there was a big rip down the middle of the tread. That one did go in the trash after that ride was over; but for smaller cuts (like ones you could stick a pencil all the way through), we've ridden tens of thousands of miles on booted tires, with no problem, and with full confidence to go 55mph on a downhill. One of the boots we all carry is a 3" piece cut out of a worn-out but otherwise undamaged racing tire, with the beads cut off. That's the extreme, the big one, and we've never used that one so far although I sure could have used it on the blowout I mentioned above if I had had such a boot back then. The smaller boots are cut from Mr. Tuffy or similar tire liners. Patching the inside of a tire is definitely not adequate, as the patch is stretchy and is intended to seal leaks, not give strength. We just use the pressure in the tube to hold the boot in place, and we never use glue or adhesive. It stays in place.