I grow my beans on a wigwam because that's what suits me at the moment. In the future I might construct a frame in a different location. A few years ago I turned up at my in laws (in their 80's) to find them in a heated argument in the garden about how to grow the beans. They finally conceded you grow your beans your way and I'll grow mine my way (worse than weans) and we'll see who's got the best beans. I don't think there was any difference so it's just what suits you and your location.