The difference is the c60 is using 3x3 mimo on 2.4g. Both use the 2x2 on 5g. The C60 might be a bit faster if you use 2.4g and your end device supports 3x3 mimo also. 5g still will be faster than using 2.4g for most people so there is no difference if you use 5g.
Range is a function of transmit power not the way the data is encoded. All routers are limited by the same legal 1 watt output power. It gets extremely messy if you try to combine the concept of data transfer rates and signal levels and try to call that range....ie what distance can I get 100mbps. This is why you see every router in existence try to claim they have better range than everyone else. There is no consistent way to rate this when everyone makes up their own rules.
Most the coverage issues are not the router anyway it is the end devices that many times have tiny antenna and low power transmitters. So they might be able to hear the router but their signal is too weak for the router to hear.
MU-Mimo and beamforming are mostly marketing hype. In general any advantage is so small it can not be detected by your average user. You can run test programs and get fancy numbers but most people will not be able to see the results in real life work. Of course those "special" people will always say they can detect it.
Your best solution for walls is to run wire though them. Ethernet is best, followed by moca on tv coax and then powerline network. All tend to be much better at getting signals though stubborn walls.