I have heard with my ears, the same shortcomings of the MA6900, which prompted me to buy the Yamaha AS2100 and matching CDS2100. I guess you have to spend much more to have sound that betters the Hi End Yamaha integrated amps when buying Mcintosh. I think 6K for the amp and 6K for the pre amp.
Mcintosh is making a lot of low end gear that cost a lot for the money but is within reach of the more affluent middle class. So you either have to save more money to buy the good stuff; at least 12K or buy really good used gear or go elsewhere, like I did with Yamaha hi end gear.