When I am traveling and visiting a course to check it out, 1-round 1-time only, I'll play whichever tee on each hole looks like the most interesting challenge. Probably 80% of the time, this is the longs, but sometimes designers stick a long tee in a silly spot just to make it tough, and the hole loses its flavor.
Overwhelmingly, most of the people I've observed out on courses I've visited, were playing the long tees.
Overwhelmingly, most of the people I've observed out on courses I've visited, were playing the long tees.