I have always loved the idea of multi-effects but my experience with them has never been that great I own an Me-25 and its sounds okay but not great.
I am trying to decide whether I should go for a better Multi-effect pedal or individual compact pedals. The M5 seems like a good mix of the two.
I wouldn't build my pedals around the M5, for me it was about real estate and alone replaced a tuner, DL4, chorus and flanger. It's like a swiss army knife for guitarists and sounds good too. Remember you can only use 1 effect at a time which means it is not like normal muliFX unit or the larger M9 or M13.
I prefer pedals over multiFX as they just sound more organic. Obviously lots more wires and can be fiddly but a pedal board usually solves this.
Beware though as Pedal fever can bite and once it does there is no turning back..........