I'm not real familiar with benelli, but I think the difference between the two is the stock and the recoil pad is a little better on the supernova, and about a $100.

If you're a benelli guy either of these would be good guns but before you just go out and buy one I would recomend looking at a remington 870 and a Browning bps. Although they cost a little more, they weigh less and they're known to be rock solid. I own one of each and they are!

Go look at all three and just get the one that feels and fits you best.
Good Luck