I bought this because I wanted a simple, one-knob phaser. I didn't want to have to mess around with all those rate and depth and what have you knobs, just the speed - so this Behringer was a good option.
Overall, the pedal is good. The sound is really nice, the one speed knob is honestly all you need, as it offers a huge variety of different sounds. The built quality doesn't leave anything to be hoped for, and this one is made out of metal, unlike most Behringers which are made out of plastic.
The only thing that bothers me, which makes this pedal nearly unusable for any lead guitar purposes, is that there is a volume drop when activated. This is actually natural to a phaser circuit - it just sucks out a bit of volume - but most phasers compensate for that by also adding a little gain, to get the volume level back up. This pedal clearly doesn't have that gain boost, so it has a noticeable volume drop. It's not huge, but it is there.
I only use this whilst playing rhythm parts, so it doesn't bother me, but if you play songs that require you to switch phaser on and off in the middle of the song, this might not be the phaser for you.