In the last sixteen years or so, I've gone strictly to semi auto's only in shotguns. My non auto shotguns don't see much action anymore. Between a few buddies and myself we currently own fifteen different semi auto models. Three of which are Benelli's. That said, the M2 is a very good gun. The Inertia operation is very clever and unique. Unique problems come with a unique design. The Benelli's have a tendency to have the bolt come out of battery accidently otherwise known as the "Benelli Click". The gun also needs to move backwards to cycle the action. On straight overhead shots when the stock rolls on top of the shoulder the gun may not move back far enough to cycle the action. Inertia operated guns tend to have more problems with lighter loads. They are better than long recoil guns but, not as good as a good gas design. Benelli's are very reliable. It's just good to know the designs achilles.
The Inertia guns are usally easier to clean to most other semi auto shotguns designs. They will usally go slightly longer between cleanings than other designs. Benelli's are also very well made, light in weight, and balance well for me. Like any other gun, they are not the best gun for everyone or everything. If they were everyone would have one for everything. If you like the gun and it fits well by all means get it. It's a gun that should last a lifetime if well taken care of.