I'm definitely a patcher. I replace tubes only when they rupture at the valve or have some other terminal failure. I also replaced a tube on the road when I had a flat at -20 C...

Basically, it takes me about 10-15 minutes to do the job, but that includes the time to get my repair kit out, remove the wheel... so I assume that it may take me only 2-3 minutes more to patch than to replace the tube. Patching is also much better for the environment.