Strum,
Compared to others I've had or heard? Well, I'll have to apoligize first to the rest of the Fretters for dragging this thread a little off-topic by going into a quick 'review' here of the unit...
The 22 different Overdrives & Distortions include 11 faithful working versions of 5 of Boss's Biggies - my favorite being the 2 I had, the OD-1 & BD-2 (BluesDriver) - and very decent 'models' of 6 others, including the Ibanez Tube Screamer (TS-808, 'the Greenie') I'd had in my board. All better than the MXR Distortion+, which was my 4th of that breed.
From what I've seen in this thread and in Fretters' sigs, or with DVM's rig, I don't think I'm alone in saying that there's no single Overdrive or Distortion pedal that's a be-all end-all if you use different guitars (single coil loaded vs HB's, for instance) and/or amps. What's nice about the ME-50 is the OD/DiS section is you can, to a degree, combine the effects of 2 or 3 of the 11 OD/Dist units with what amounts to 11 preset combos of them.
The Mono & Stereo Chourses and Delays are on a par with Boss's big guy multis of those devices, maybe giving up just a bit of fine adjustment control. The Reverbs are decent, and independent of the Delay section.
The Expression Pedal is a little tricky because it doesn't have the 'travel width', particularly of a Cry Baby Wah; you need to be 'light on the foot'. So those who use a Wah 'extensively' may not dig it. For that touchiness reason, too, I prefer, still, to use my old Goodrich photocell Volume Pedal after this, and while the onboard Tuner is pretty good in pinch, I still count on my Boss TU-12H for crtical tuning.
I traded my 30 yr-old board loaded with 'vintage' stuff, some pretty beat up (stomp boxes, right?): the Cry Baby and those 4 Distortion pedals, plus an old Ross Flanger, an MXR Stereo Phaser, MXR Stereo Chorus and MXR DynaComp Compressor and a Boss NoiseGate, a power supply and all the little cables and patchjacks for this, even up. All I had to buy was the PSA-120 AC Adapter (it also runs on 6 AA's if you need it to).
I feel like I got everything I had in that board, or at least used alot, plus I got a Harmonizer, an Octaver pedal, and more.
The biggest advantage? a lot less signal degradation and invitation to interfereence & noise from all that daisy-chaining. One plug in, one plug out.