I feel that the quality of the videos of some BB5 models are lower in quality even those are newer model and even those have higher processing speed.As an example I feel N70's video is better than N80's and N71's. What do you know about this. I think the best way to compare this only from watching of a video of each model. Please upload a small video clip which have captured by yourself with the best quality settings with the in-built Nokia video recorder. Hope this will help to all.
Good Luck.