I might also stick with them (Denon-Marantz) but when I chose the NAD it was the ease of operation, switching inputs and outputs modes, that swung me. Perhaps because I use it primarily for music and not movies it was the better choice for me.
I'm actually more enthused about it now because I paid $700 for it in December 2015, another $200 in June 2017 to upgrade the video for 4K (and added Bluesound streaming.) Now for $630 (less the discount my dealer gives me) I'll be upgrading it again to get Atmos capability and Dirac Live for $99.
Seems a lot, but it's like getting a new receiver every couple years for cheap. It's the Dirac Live which intrigues me the most, as I rarely watch movies.
The T758v3 with all these features for $1299, though only Dirac LE unless you upgrade for another $99. Same with the more powerful T777v3 for $2499. I don't know why they haven't made the same upgrades for the top T787, maybe it's going away or being replaced by something completely better as a flagship unit.