So is it just PSX games on the main site that are bad dumps or are other systems games affected as well? Should I only be concerned with bad dumps for PSX games?

I have been reading around and it seems that lots of multi track games have not been dumped very well and have not been converted very well into single/combined track games (missing some of the tracks, data, audio etc.). Is it just multi track games on the main site that are bad dumps and games that are originally single track (although not redump) being good dumps? Or can both multi/single track games be bad dumps?

I also hear Redump is the best for Disc images and No-intro is the best for cartridge roms. So are these the ones to go for?