Pre-purchase I only knew the Phase 90`s sound from modelling softwares and loved the sound immediately. The actual pedal sound even better for me and the versatility you get is really surprising. Turned all the way down it has a lush, slow phasing, suitable for anything really. The 10`clock setting has a nice funky vibe, and if you pass 12`clock you slowly land in vibe territory. The rightmost position is great for some harmonic notes or even for slow rythm sounds.
The effect is never harsh or to much, it settles in nicely with your guitars natural tone. Some people mentioned the noise it might create. Yes, it is a little noise, but it is a deep, barely noticeable humming and I only used it in front of the amp so far, maybe its even quiter in the effects loop. Bear in mind however, that this is just a characteristic of the BucketBrigade chips the pedal uses. They are an older technology and noisy by nature.
The pedal also comes with a rubber knob, which lets you adjust the rate by foot, and it`s very convenient. Just dont forget to apply some velcro to your pedalboard, so that it wont slide back and forth while you are turning the knob.