The configuration of the Boss CE-3 couldn't be any easier to figure out, as it only has three basic parameters and the general set up of the pedal is quite easy as well. The knobs on the Boss CE-3 are for rate, depth, and a stereo mode for choosing between the different outputs. This gives you a good amount of versatility, especially if you are into using stereo signals for guitar. I don't have a manual for the this pedal, but it is easy enough to use that you don't need it.
The sound quality of the Boss CE-3 is very warm and rich sounding, and will certainly provide you with a nice sounding chorus tone. I have only used this pedal with guitar - usually a Fender Strat or a Gibson SG and a '76 Fender Twin Reverb amp, and I find I always get tones I am happy with, whether it be for recording, practicing, or live shows. Since this is one of the older models in the Boss chorus pedals line, it has a warmer tone than some of the newer digital pedals that they make in my opinion. I would encourage those interested to try a bunch of different chorus pedals to see what will work best for their situation.
I've been using the Boss CE-3 for a few years and have found it to be a great all around chorus pedal. It is very easy to use and set up, while it doesn't compromise sound quality in any way. It has a cool look and color to it, and since it is made by Boss you know you are getting a well made product that will last for a long time. The price of a used Boss CE-3 isn't all that expensive, but I would again encourage those interested to try it out before buying, as well as to try out a few of the other chorus pedals that Boss and other companies offer. Overall, the Boss CE-3 is a great choice for a guitar chorus pedal.