Let me preface this review by saying, I am in a 3 piece, so being the only guitarist, I have the job of filling space and adding dynamics when parts of certain songs get too mundane and "dry". That being said, the only modulation pedals on my board are a DD20, and this RFX970. Here is why: I bought this pedal as it sounded like a rotary speaker upon demoing it in the store on the clean channel of POS combo, and was so versatile my mind couldnt wrap around it in a 5 minute demo session. (plus after checking prices on ebay,) it would have been dumb to pass this opportunity up. Ease of use: Very simple layout. You have 4 knob controls - Depth (controls the intensity of the tremolo. It can bend a note up to a half step down, this controls the severity of the "dive".) Speed (controls the speed of the tremolo effect, as well as the flange) Manual (controls the intensity of of the flange effect. can go from subtle to INSANE AIRPLANE without issue) Peak (controls the pitch/note at which the flange effect peaks. It can sound like a brisk wind or a blizzard) Features: Has two modes with independent switches, as well as stereo out (plus another little goody Ill address) Built in noise gate Two footswitches: with the Flange activated, and "mode one" off, you will be getting a mixture of the wet and dry signal. With both switches on, (i.e. Flange and Mode 1), you are getting 100% wet signal. Stereo output, need I say more? Maybe I should, when using both output jacks, one becomes strictly a wet signal, and the other strictly dry. My favorite feature. You can hook a 1/4" headphone jack to either of the outputs, and eliminate having any sort of amplifier for practising and noodling at your desk. Reliability: I have never had an issue with this pedal, however stronger components would be a tremendous step forward in the right direction. That being said, this pedal has withstood the test of time, and I learn something new about it every day. Value: I picked mine up on the used market, however if you see one under $55, you will be doing yourself a disservice passing it up. Customer Support: Im pretty sure at this point it is non existent Expressiveness/Sounds: This is what originally sold me on the pedal. Not only does it have a beautiful tremolo and flange effect, which can be tweaked to operate one way or the other, but I have found that setting the controls to noon, and tweaking slowly on a clean channel gives me a beautiful chorus that even a Small Stone couldnt rival. It will also emulate a rotatory speaker. It can be a subtle ingredient in your tone, or you can make it sound like a space station exploding. It takes a while to fully grasp how immediately responsive the controls are, but once you master it, you quickly learn that it is more than a run of the mill Trem/Flange . It has become my favorite pedal on my board, because if I ever need a Chorus effect, it is easily dialed in on the Vibraflange. On top of all of the other insane noises it can produce.