For a sd receiver the sound and video quality on the 500/600 is excellent. Ok there isn't a ton of img's out there for them ... but the ones there are work well.
most of them are crap imo although for use on a fixed dish there fine. ive owned a tm600 and own a tm500super now and both of them refused to work with my stab 100/120 motor and sent the dish wherever they felt like no matter what image i tried. i could never get mgcamd 1.38 to run on mine either although as ive said i have one here set up for 28.2e with C**am 2.2.1 for test purposes and its fine,regards mdt