I own both, so obviously that makes me an expert.
Honestly, I haven't fired the two enough to make a strong comparison. I'm not sure I'll ever fire enough to wear either out, although I got the 870 used so it's got a head start. However, the Remington is chambered for 2 3/4", so it'll never get the workout of the 3 1/2" & 3" turkey loads the Benelli will see.
What I've noticed (for what it's worth):
The trigger on the Remington is narrower, giving it more "play", or side-to-side wobble. I really didn't notice this until I shot it the same day as the Benelli. The Nova has a wide, stable trigger.
On disassembly, the Nova wins hands-down. No tools are needed to pull the thing apart (the magazine cap is the disassembly tool). Not that the 870 is hard to dissasemble, but there is some finesse for operations like putting the trigger assembly back and getting the bolt & slide in together. The Nova comes apart and goes together like legos.
Both feel solid, although the traditionalist in me likes the feel of my Wingmaster's wood over the Nova's Star-Trek plastic. The Nova has that rattle in the forearm, but it's not a terrible thing (unless that sort of thing REALLY bugs you).
This isn't a durability issue, but as for fit the fore grip on the Nova is quite a bit further forward. It can be gripped further back, but it's not as comfortable in the hand. Because of the longer reach, I found that I wasn't naturally shouldering the gun properly - the butt was landing on the ball of my shoulder instead of in the pocket between my shoulder and chest. The problem is that I didn't notice this until AFTER patterning turkey loads. OUCH! Practice and familiarity should resolve this.