Brother in Law has a Marlin and a Ruger carbine in 9MM. He also has Beretta CX4 carbines in .45, .40 and 9MM.
I have had the opportunity to shoot them all, and they can be a lot of fun.
For the weight and size though, I'd pick something else for home defense.
The Marlins look fairly light and handy? Certainly a lot lighter than a typical 12 gauge semi auto?