The use of the pedal is pretty easy to follow. The general configuration is straight forward - there are two sections, one for voice mix and one for filter sweep and there are ten sliders total. While it is easy to get some cool sounding effects with this pedal, I sometimes have some trouble with getting consistent tracking on it when playing. This is the really the only downfall of the pedal. I don't have a manual, but it would probably come in handy as there are a lot of ins and outs of this pedal.
The sound quality and effects on this pedal are generally pretty good sounding and realistic. In terms of whether or not you can really turn your guitar into a synth, I would say not. That being you said, you can get some really cool and interesting synth like tones from this and it is an interesting tool to say the least. I have only used this with guitar, as it is really made for guitar, and they make a separate version of this for bass guitar.
I first used the Electro Harmonix Micro Synth about four years ago. I was really curious in exploring synth like sounds that could be made with my guitar. While I'm not completely satisfied with this pedal in terms of that, it can do some pretty cool things and I have found it a useful tool when trying to explore new sounds with a guitar. I like this better than the Line 6 FM4 which also has some synth like sounds. While the tracking isn't great on this pedal, it is better than the FM4 and to me the overall tone is more authentic sounding. The price isn't all the cheap, but I would encourage those interested in this pedal to go down to the local store and see if it is for them before buying!