The MXR Uni-Vibe is, as far as I know, the third generation of the legendary rotary effect. The original, made by Shin-ei and immortalized by Jimi Hendrix on “Machine Gun” and David Gilmour on “Breathe”, was a big honking unit, typewriter-sized and with a separate expression pedal to control the speed. The later Dunlop reissue was in a boutique-style chassis with regular stompbox controls and two footswitches: on/off and chorus/vibrato (“chorus” mixes the clean signal in with the effected signal, “vibrato” is effect only). This third generation packs all of that into a standard MXR mini enclosure with three knobs, an on/off footswitch and a small VIBE pushbutton. It is pedalboard-friendly and built to the usual MXR standards, i.e. like a Sherman tank.
In a sense, I’m a little bit bummed that I bought this only after getting the TC Shaker and the MXR Phase 90 and Micro Flanger. It is not really a phaser, not really a vibrato and not really a chorus (and definitely not a flanger), but a little of everything. The most important thing is that it totally nails the classic Uni-Vibe tone. Maybe not waveform for waveform, but close enough that I can put a Stratocaster through my Blackstar and pretend I’m Jimi or Dave for a moment and wear a huge smile on my face. It might be a bit of an exaggeration to claim that it will replace anything on my pedalboard, but it is a very nice addition to my arsenal, especially for late-60s/early-70s covers or a general psychedelic vibe. (Nothing can make me give up my Phase 90!)
I am not particularly bothered by the fact that you have to reach down to set the speed, or switch between the two effects manually. As I’ve already mentioned, I have several coloration pedals, so if a song really needs two different effects, I could probably make do with the flanger or the vibrato. If anything, the vibrato setting is a tad subtle, it needs some speed to really make itself heard. And the level control doesn’t work the way a level control usually does on a pedal of this kind: it raises the general output of the pedal. Handy if you’re looking for a bit of boost to your Fender sound, but use with care if you want to balance clean and effected sound.