I bought an ME50 when they first came out. I already had several amps and amp simulators - so I did not need a pedal board for amp sounds, I just wnated lots of pedal options.
As already indicated saving settings does not cause the knobs to move - naturally this means you can't always trust your eyes. As an example the knob may indicate a setting is at 2 o'clock but the actual setting (in memory)is 10 o'clock.
I consider the ME50 to be more of a "real time" pedal board for live application (into a guitar amp) rather than a recording tool. You can quickly turn a knob to alter sound, rather then call up parameters in a window) If you've done your homework you already know there is no amp modeling. I find that for whatever reason the ME50 sounds better as a front end to an amp rather than into an amp simulation (perhaps this is more of an indication on the weakness of amp simulators)
I can't attest if the effect simulations are accurate compared to the original pedals (I'm a drummer more than a guitarist - so I never owned any of the original pedals) - but I can get just about any sound I try for out of the ME50. I really wanted knobs to tweak rather than windows to scroll through.
There are 3 or 4 distortion "pedals" I use, the rest seem too extreme for what I play. The chorus "pedals" and the delays are very decent. The compression is actually very good. The "eq" section is not very good and I always have it turned off.
Based on the various "user reviews" I've read (there are several on Harmony Central) the ME50 seems to be a love it or hate it piece of gear (although it seems a lot of gear falls into that catagory).
All I know is - it works for me.
