I run (quite poorly to be fair) an M2 for 3 gun and if you get the Benelli definitely mod/update the lifter to remove the 'U' portion if that is still the stock configuration. The beveling of the loading area is great for dual or quad loading but for a defensive weapon you would be loading singles so nice but maybe not helpful? Never had any issues with light loads, slugs, etc. A 21" barrel with take roughly a 8 shell extended tube and be close to flush so hopefully with 8+1 you would not need to be reloading much.
You may end up getting more responses to your question asking why you would choose a semi auto shotgun for home defense than feedback on the shotgun itself