I like to do weekend rides, centuries, trips to the market, and every summer I take a long, fully-loaded tour. I think a dedicated touring bike is the way to go, since it also does those other things well. I think it's a better choice than buying a non-tourer for those other chores, and taking it on tour. When I'm out in the middle of nowhere with a full load, I want a bike that's made for that sort of thing.

I say if you're really going to tour, buy a tourer.

I have a Surly LHT and I love it. There are plenty of other good choices.