Basically, the difference is this: phasers are warm and squishy, flangers are metallic and sound a bit like you’re playing in a wind tunnel. I find the phaser has a more interesting sound at the top and bottom of the sweep, whereas normal flangers are more interesting in the middle of the sweep (unless it is Puretube’s Flanger Hoax, in which case it is interesting all the time no matter what).
The Worm should get you close to that “Breathe in the Air” tone, as well as offering you tons more awesome modulating stuff. I haven’t played the new XO version but I’ve heard rumors that it even solves the noise issue the big box was notorious for, so that’s something to be excited about.
I can’t think of a specific song from The Wall off the top of my head, but comparing the guitar tones on Dark Side of the Moon to The Wall is basically comparing phasers to flangers.
