This is a tough one to review in some ways. I think if I look at it through the lens of "what does one expect from a 70s quad recording?" I guess I think of a format struggling to gain a foothold in the market, coming out of the gimmicky stereo years where things bounced from one speaker to the next, and so the first thing one might expect is a gimmicky mix with lots of stuff bouncing around, or maybe the "hard pan" approach seen in some late 60s stereo recording where maybe each speaker gets its own instrument. But these, while meeting some of those expectations, also have very modern elements where, for example, the rear speakers are treated as a stereo mix for some vocals and instruments while the front speakers blast different elements entirely resulting in a very modern surround experience. The fidelity. The Doobie Brothers were well recorded and the bass on these is very well done as are the drums. Interestingly (and I am sure this has been mentioned somewhere) Ted Templeman, their producer, was the lead guy for Harper's Bizarre, whose big hit was the 59th Street Bridge Song (Feelin' Groovy), which I loved as a kid. So if I am wearing my 70s lens, these in total are a 10.
If I am looking through a more modern lens, the fidelity of the recordings is still a 10. Song quality is not a surprise, it's high quality throughout. Musicianship is also top notch. Of the four blu rays I think Captain and Me is the weak sister SQ-wise, but not enough for a demerit. Toulouse Street, What Were Once Vices, Stampede are all of extremely high quality, if C&M is a slacker a bit, well that hardly qualifies as a complaint. Each album has at least one really strong "goose bumps" moment. I really get the feeling that the production team "got" quad, and these are awesome. Through the modern lens these would probably be a strong 9 up to this point. Add thankfulness to get these at all, and the great value for the price, and we are again at a 10! Thank-you Warner/Rhino, I hope you sell a ton of these. And my thankfulness will last a month, and then it's back to "more please....!"