One major advantage that modern Marantz (and Denon) receivers have is that they can equalize the response of the subwoofer. Yamaha receivers can't.
Marantz uses Audyssey room equalization software, while Yamaha uses their own proprietary YPAO. Unfortunately, YPAO does not equalize the subwoofer or frequencies below about 35 Hz. Audyssey does. In general, room equalization software can make a substantial improvement in the quality of both music and movie sound tracks.
Other than that, you should carefully go through their other features to see which best matches your requirements.
Marantz SR7009 avr + MM9000 amp --> Atmos 7.1.4
Fronts=NHT 2.9+AC2, FH+TM=DefTech PM1000, LCR+TM amped