The 'tube failure' theme is a recurring thing brought up by those who have never patched tubes. If you just follow the very easy directions, it's almost failsafe. I wouldn't patch if there was a significant patch failure rate - I think I've only had one patch that 'might' have failed, and it was one used on a bike trainer (high pressure contact on the rear wheel) and even so, I'm not sure it was the patch vs the valve as it was a slow leak. Even now, I've got a tube on my trainer with 2 patches on it, and all the tubes in my race and training bike have patches on the tubes. (I clearly don't buy tubes that often.)