I have the VP1 phaser, the UP100 phaser, the PB100 gain/EQ, the ADI21 EQ/Preamp/DI, and the HF300 flanger. I got into effects pedals about 2 years ago, and I originally bought Behringers because they're cheap and I've read some good (sometimes great) reviews about the ones I was interested in. I'm purely a home studio guy, so I can't comment on the build quality, durability, etc. However, the sound quality of all of these pedals is excellent for my uses. The VP1 has warm, deep 4-stage phase tones. Also, I accidently discovered that when I put the Tone switch in the middle, I get a phase tone that's right between the subtler down position and the deeper up position. Nice! The UP100 is not nearly as deep, but it blends in with my keyboard's tone better than any phaser I've tried. It's not weak or just along for the ride; it really becomes a part of the tone. The PB100 is the perfect basic boost/EQ pedal. Nothing fancy; it just does the job. I got the ADI21 out of curiosity, wondering what it might do to warm up certain tones. What I wasn't expecting was the strong, growly overdrive and the killer stuck wah sounds I got from this baby. It also has some deep sub tones in it. The Mid Freq and Blend knobs are the difference. The HF300 does what I want a flanger to do: add a nice texture to my tone. I'm not looking for "jet-plane swoosh," although it might be able to do that. It also does a sweet chorus which can be quite vowelly if you want.
I understand why some people have ethical issues with Behringer's rep as a pedal clone factory, and many are concerned about durability, but for my home studio uses, Behringer hits the spot.