Totally non applicable to you because every situation is different but here is my story.
I found I gained a very satisfying increase in quality by using the tests and color eye filters provided with the Avia disk. It removed some coloration issues that were not bothering me but were never quiet right. More importantly, it all but removed my trouble with the snowstorm effect on large patches of light colors like a grey or light blue sky. That one was bothering me. HD was crystal clear except looked like VHF signal whenever there was large patches of light color.
Interestingly enough, until the tweaks removed this effect, I couldn't stand watching my first HD movie, 300, which many others tout as reference quality. It's painting like backdrops looked like fuzzy crap until I calibrated.
