I always thought the Saiga 12 shotgun was the ultimate. I may have to change my mind. Check this out. http://www.keltecweapons.com/news/preview-kel-tec-shotgun-ksg/ This thing combines huge capacity, reliable (hopefully) pump action and a short overall length. Plus, it's a lot cheaper than a tricked out Saiga.
Yes it is . All these weapons are very good copies of European firearms. For home defense ,the semiautomatic weapon is the best. If you are injured, who is going to pump your gun for ya ?
The barrel length is over the required length (18 inches) so it is legal. It is the "bull pup" design that makes the overall length shorter. P.S. I am not entirely sure if the length has to be 16 or 18 inches. I own a 16" rifle which is legal but I don't know if shotguns have different requirements.