I think this is a great thing because as someone pretty new to surround audio, I'm always finding some random album that was released in quad there or 5.1 over there, that I've never heard of before. No matter how many "definitive list of x format" lists I look at
Regarding '70s quad releases, I would consider this site definitive:
http://www.surrounddiscography.com/quaddisc/quadindx.htm
