As yet another frustrated guitarist, I've been exploring the fantastic sounds than can be obtained from ukulele, but I've always had a soft spot for the sound of the mandolin.
The M20 represents damn fine value for money, but at this price, do not expect it to be playable from the box. The bridge isn't fixed, but held to the body by string tension. It moves during shipping throwing intonation out. Way out in the case of mine. Imagine you're a total beginner. You tune up, play a chord and it sounds, well, 'off'. The action on mine was higher at the 12th fret than the action on my Fender Precision bass!. I had to carve 2.5mm from the bridge to get it playable.
Once the basic string height and intonation are set, it becomes very playable indeed. The supplied strings keep tension on the bridge and keep the neck in order. Budget for a restring. Once set up, it fair sings and like a Uke, brings a daft grin to the face as things fall into place. Highly recommended with the setup caveat.