Pros - -Warm, very musical phasing
-Legendary nuclear bomb-proof Boss build quality
-Depth knob makes it very versatile
-Looks pretty nice
Cons - -A little on the expensive side (but easy to resell for the same price, if not more)
-No feedback knob, which prevents insane sweeping and ray-gun effects
-Some low-end drop off at one point in the cycle
I initially bought one of these pedals around June, but it was defective and I had to send it back. In the meantime I bought a CE-2 before I finally acquired another PH-1, and I sure am happy for doing so! This small green box is a very warm, musical sounding phaser, not unlike the MXR Phase 90, which I feel it beats thanks to its inclusion of a depth knob, allowing for varying intensities of phasing. Some of my favourite settings are (rate and depth) 2:00/5:00, which gives a nice shimmer to the sound, 9:00/5:00, which gives a long, Van Halen-like sweep, and 5:00/1:00, which gives a leslie-esque wobble to the sound without going over the top.
One thing I will say is that you will benefit from putting this pedal through a clean blend, as at one point in the cycle (more noticeable the lower you set the rate and the higher you set the depth) the low-end drops out a little. However, I generally use the 2:00/5:00 setting, in which the low-end dropoff is very quick and barely noticeable, so I don't bother. As a bonus it also sounds incredible on guitar!
Overall: Good if you don't mind a little low-end drop off here and there and you want some gentle bubbly phasing. Not so good if you want space-age madness!