I used to weigh as much as 220 lbs (down to like 190 now), and had a bike with the dreaded Bontrager "Paired Spoke Technology" wheels with a low spoke count. I rode them for thousands of miles, and never had an issue. I never even had to true a wheel.
Another friend of mine is about 250 lbs (guessing based on appearance), and he has been busting spokes like crazy on 28 spoke wheels. There clearly seems to be a weight in the 200's that causes problems with spokes, and it must truly depend on the exact products you are using.