Pros
Growing company with lots of opportunities. The company strives to provide a rewarding experience for all of its employees and places great emphasis on personal growth, providing ample opportunities for those it hires to better themselves. Multiple people, myself included, have found opportunities within MOD that would have been hard, if not impossible to get elsewhere; and the corporate office is filled with people promoted from within the company. MOD has a very inclusive company culture, full of people from all walks of life, and "being yourself" is encouraged. This, coupled with the fact that at an hourly level, all that's really required is a desire to work hard, means that you'll find some very interesting characters working at a MOD. The pay is pretty good for what amounts to a fast-food/fast-casual job, and the access to health benefits after just 20 hours a week is fantastic for an hourly position. The leadership of the company likes to be personal (though some are so more than others), and depending on where you are you can easily expect to see members of the executive team stop by to say hi and interact with their employees and customers. If you work at a good store, MOD can be one of the best jobs you'll ever have. But that caveat of "a good store" leads pretty well into the flaws the company has.
Cons
Depending on where you are, a lot of things can be a mixed bag. Because MOD will hire almost anyone willing to work hard, you can get bad apples along with the good ones. In successful and more established stores, the bad apples are weeded out without outside influence, but if a manager isn't that great, or a new store is rushed through the hiring process, poor employees can linger and cause problems. This leads to the second main fault with MOD, that being when a store can't handle itself well the operations team comes down like a hammer, and the wheat burns with the chaff. When expectations aren't met, everyone feels the heat. This means that struggling, or poorly managed stores can be a rather bad experience for everyone involved, turnover is high, and it becomes even harder to drag a store out of a rut.