Hi your not alone with this problem
,
I had TiVo installed 3 weeks ago and my initial reaction was the same as yours with PQ being my main gripe,
I do believe VM will fix it and they have been very positive about the problem
I decided to stick with it as the TiVo features are fantastic, my PQ as improved after, adjusting my TV settings
my engineer left my picture settings to stretch (full screen) on all programmes, I found this distorted the SD picture on programmes shot in 4.3 format
I changed this setting to Panel, (in Settings Video) this really improved my SD PQ, HD for me was alway good
You will make your own mind up but for me I would stick with it, because as you use the box more you will see its brilliance
The suggested recording have introduced me to TV I didn't know existed, I would not go back now, but did feel like you directly after my installation
Good Luck
