I have a SuperNova tactical and I love it. Right out of the box, it has ghost ring sights, can shoot 2 3/4", 3", and 3 1/2" shells, and has the feed stopper button that allows you to cycle the action without feeding another round for the tube. The last feature is useful if you needed to quickly load a slug directly into the ejection port without the gun feeding a round from the mag tube full of buckshot, ect.
The supernova has the comfortech stock, which is nice. Doesn't reduce the recoil as much as Benelli claims, but it is slightly noticable. Also, the fore-end doesn't rattle like they did with the previous Novas.
Some of the downsides I've noticed is that the comfortech stock is not as sturdy and reliable on the earlier models. The stockpad cage assembly are notorious for popping completely out on the earlier SuperNova models. Mine did that and you basically have to epoxy the whole darn thing. Benelli seems to use a very conservative amount of glue on those things. Also, the stock probably wouldn't make for a great boat oar or club like you could with a traditional stock
The most notable downside is that it has one of the worse triggers for a shotgun. It's heavy and has a flex feeling before it breaks. Not much of an issues since it's a shotgun, but it's still a little annoying.