What if you want less resolution and smoother framerates with less tearing?GTA4 on the PS3 is 640p, so it upscales to 1080p using the SPU method. GT5 at 1080p actually has 50% more resolution, thus sharper, crisper visuals compared to GT5 at 720p so it's not an apples to apples comparison.
TBH I'm not sure what you're even saying. 1080p output from PS3 is always better than 720p output? That's not true as there are usually compromises to get 1080p, hence the forcing of 720p. In the case of a 720p panel that supports 1080p input, like all the EU ones that are HDMI ready, 1080p output gives no increase in fidelity but does have the rendering or upscaling impact, so disabling 1080p certainly makes sense. Most other games I've seen render in 720p by default with very few upscaling to 1080p unless forced. I don't know if anoyone's (DF) done a study into how forcing scaling affects tearing and framerate to get a real cost.