They are both quite good actually but also radically different. I can tell you that with my general gaming group we have played Zombiecide a ton.
Mice and Mystics is great where you can count on a small group playing regularly to complete the story line. You can do each chapter as a one off but that is not as good an experience.
If you have a large group that has new people popping in and out often Zombiecide might be a better bet.
Mice & Mystics is focused on the great on going story and is less strategic (M&M combat is very simple) than Zombicide but Zombiecide story is light and sometimes hardly even makes sense...but, it is a zombie game so what do ya want.
You really can't go wrong either way.
Mice and Mystics is great where you can count on a small group playing regularly to complete the story line. You can do each chapter as a one off but that is not as good an experience.
If you have a large group that has new people popping in and out often Zombiecide might be a better bet.
Mice & Mystics is focused on the great on going story and is less strategic (M&M combat is very simple) than Zombicide but Zombiecide story is light and sometimes hardly even makes sense...but, it is a zombie game so what do ya want.
You really can't go wrong either way.