Reviewers are asking - not unreasonably - "what is the point of this album?" As a number of people have pointed out: if it's a Floyd compilation you're after, then the decade-old (eek!) 2CD set Echoes contains almost twice as much music. And now it's been deleted - ho hum!
I think I may have the answer to the question though: this is a compilation for Alice.
Alice is the name of my delightful ex. She worshipped Radiohead and Blur. My liking for 70s prog largely mystified her, though. However she `got' the Floyd - or at least Dark Side of the Moon (a sort of 70s OK Computer) and Piper at the Gates of Dawn (heartily ransacked on Blur's Parklife album).
If I had slipped the Echoes compilation into her Christmas stocking she would have stalled at Set the Controls and the eponymous Echoes. She would have yawned theatrically at relative makeweight Marooned. A Foot in the Door would have worked perfectly, though. There are no deep-space freakouts (which I personally adore) and a focus on the concise accessible gems from Dark Side, Wish You Were Here and The Wall (the selfsame albums getting the fullest reissue push. Draw your own conclusions)
Shockingly, only See Emily Play remains on board from the Syd Barrett era - potential Alices may wish to supplement this compilation with Floyd's classic 1967 debut album Piper at the Gates of Dawn - a non-stop psychedelic tea party of literate whimsy and only one deep space freak out...
So, if it's a career overview you're after, then seek out the splendid Echoes compilation. However, Foot in the Door is an all-killer-no-filler compilation for the cautious beginner and the driver that craves a swift succession of musical knockout punches on their car stereo. The title sums up its strengths nicely - to mix metaphors it dips a cautious toe in Floydian water. It answers the marketers' current rhetorical question "Why Pink Floyd?" with a concise answer: "It's the songs, stupid!"