I have a pair of 901 Series II, that my old man bought in '75 or '76 and gave me a couple of years ago when he moved into a condo. I always loved them as a kid, and they look very cool in the living room.
As far as direct/reflecting theories that Dr. Bose developed and integrated into speaker designs in the late 1960s, I have found them to work exactly as he described in his AES papers on the topic.
Unlike normal box speakers with the drivers facing front, there is no real "sweet spot" in the room, in other words you don't have to stand within a 3 foot circle in the middle of the room at the tip of the speaker "triangle" to hear the best sound.
With the 901s, you can move all around the room and the sound seems to follow you and never phases or changes the EQ. I have also read for years all the bashing of Bose 901s, and I never understood it at first. My old man's system sounded incredible with his classical catalog, both with the reel to reel he had, as well as the turntable. My early Dead masters sounded sweet too when I was home from college.
I remember hearing some later versions of 901s over the years, I think they are up to Series VI now, and sometimes they sounded just terrible. Every negative comment I read was represented. Then, I got the old Series II from my Dad and during the setup process, it all made sense.
If you place them to far apart or too close, noticable decay in quality. If you place them too far or too close to the back wall, same decay. If there are pieces of furniture too close, or a bunch of junk behind them like book cases, artwork, etc, again, serious decay in quality. This is because the theory of direct/reflecting sound reproduction has as it's most important factor accurate coupling of the speakers with the specific room. Also, I have never heard 901s hanging or otherwise off their pedestals that sounded right.
Once I dialed in the correct placement in our nice wide living room, it was like there was a plastic bag over them that was lifted off. So, my opinion of people that cannot hear good sound from Bose direct/reflecting is the pair they heard were simply not setup correctly, or the room was structurally not optimal for them.