I've never heard of Duron, sorry
I found their website and dealer finder and punched in a few states around me and they have no dealers around here
Then I punched in a few states around the country and found no dealers
I got tired of punching in states before I found one
Maybe it's a regional brand?
That's not always a bad thing, sometimes it's better
But it can make it hard to compare
Duron is good stuff from what I hear. We don't have them either, but know of painters who use them. I don't know their lines of paints either. Hopefully your contractor will use their top line. If you trust this contractor, and respect his opinion, I think you will be fine.