There is one drawback to using the NRC charts to decide on speakers. There isn't anyone in the world that can point to a chart, and say "Everyone who listens to this set of speakers will like them (or hate them)". There just flat out isn't anyone who can do interpret the charts like that. If the chart is all over the place then most people probably will not like the speaker. People's tastes vary so much, that I'm sure a lot of people prefer the speakers with the worst chart.
I can't tell anything about which of the speakers in that list that I would like the best based on the charts. If I were buying right now, the charts would not be able to help me decide.
I don't care what the M60 chart looks like, I like the sound. Maybe it's a good thing there isn't an M60 chart on that page. I might read it and see some nasty hump, then stop liking them. (I'm not being a smartypants here - If If I saw a nasty chart on them, it would bug me forever. i'de be trying to hear it, instead of listening to the source from then on. Some things are better left alone.)
