Yeah, if you have enough space outdoors, the free-standing panel is the way to go if you are actually generating and storing energy. If all you want is solar-heated water, I imagine the roof makes more sense.Do not let them penetrate your roof! Every penetration point is a potential leak in the future. The new tech uses a saddle-like roof mounting system.
If I had the bucks, I would go for the pole mounted System in the front yard that auto rotates to face the sun. A lot easier to maintain and repair, imo. Lots of pros and cons no matter which way you go.
Yeah, if you have enough space outdoors, the free-standing panel is the way to go if you are actually generating and storing energy. If all you want is solar-heated water, I imagine the roof makes more sense.