I compared M40x and Pro82, I would not say that Takstar plays much better, they play approximately at the same level, the difference in sound is only that M40x has a more detached and boring monitor sound, and Takstar has more fun and musical sound.
I also compared the Pro 82 and Shure SRH440. Shure has a more natural sounding timbres and a more adult sound, but they are inferior to a Pro 82 in terms of bass.
I enjoyed the M40X but agreed that the sound is too monitoring as you say.
Somehow, the details retrieval and imaging seems to be way better on the Pro 82. They are only on par in terms of soundstage's width, but the Pro 82 still hits a little deeper with better instruments separation. IMO, the only way M40X could be on par is to get a pad mod.