I love my M13 more every time I use it. It's very simple to use. The manual does come in handy occasionally, but it's mainly useful for learning how to get into the setup screen and what to do while in the setup menu. It's quite easy except it can be a little confusing figuring out which place to set the FX loop.

I use 4 cable method. I have my M13 set in 4-3-2-1 mode, and have the Loop set to "post fx4." That puts FX 1-3 in my amp's FX loop, and FX4 in front of the amp. Once you get that stuff worked out, the M13 is pretty much like using individual pedals like echoraven said. Just punch up an effect and mess with its settings until you like it.