Is there a huge difference in quality between 720p and 1080p? I specifically mean those released by fansub groups (if the forum rules don't forbid asking such a question). My computer screen is only 17 inch, so probably won't notice the difference between 720p and 1080p.
When sub groups release both avi and an HD 720p version, I always download and store both.
I did notice that 720p HD looks "cleaner" and sound a little better than the avi.