In summary, I will echo what's been said already about this collection. The films are worth having, because after 70+ years of existence, this is apparently the best Universal will do with the classic Marx Brothers performances of their day.
Now I will heap on some gripes of my own. First, there's just over six hours of material spread over six DVDs. You do the math--they're obviously NOT TRYING VERY HARD here. They could have easily fit this all on 3 discs, or fewer. It's not like there's a COMMENTARY TRACK or even a RESTORED PRINT that would make each film worthy of its own disc. Universal did the BARE MINIMUM knowing that real fans would buy these crappy prints anyway, and will pay again if they release restored and augmented versions later. (The Warner Collection beats this one hands down, but with different titles. Hell, even Universal's treatment of ABBOTT & COSTELLO was done better.)
The "exclusive book" is fluff; it has credits and pictures but NOTHING you can't get elsewhere (like IMDB). And the "extras" disc is pitiful. The Today Show interviews of Harpo and Groucho are so brief, and in need of restoration themselves, they're actually cruel to watch. C'mon Universal, this is the BEST STUFF you could find? It's not like you were limited to supplemental material from the 1930s. These interviews are from the '60s and '70s!
The only thing that remotely redeems this collection is the price--the Amazon price, not the retail price. Buy this for the movies if you love them, but this is a collection that ONLY MINNIE (the Marx Brothers' mother) should love.