Magnepan MMG or something else

I have 3.6's, and had the MMG in the same room. Spring for the difference, get the 3.6, it is better in every way except price. The MMG was too small sounding and not detailed like the 3.6.

I had a Fiat 500 in my garage, not nearly as good as my Ferrari though both made in Italy.

Maggies sound is very sensitive to placement in the room and where you listen from accordingly. Have you tried tweaking the placement for best sound at you prime listening position? There are lots of possibilities on how to place MAggies that can have a big effect on their overall musicality.

Most good mmg setups I have heard are strong on musicality and micro-dynamics but weaker on bass and large scale dynamics. Could large scale dynamics be the aspect of "musicality" that is not happening?

If mmgs alone are scoring with bass levels but not musicality, that could well be a setup problem.

Regarding macro-dynamics/slam, if that is the issue, the common solution worth a try is to add a sub.

IF all this fails, then it might be time to move on but I would do whatever might be possible to max out performance of what you have first before making that decision.

Were you to move on, I would recommend a decent pair of Dynaudio monitors might be a good option. I also like OHM Walsh speakers in that they have a lot of planar-like musical traits but also excellent dynamics overall.

Have you considered replacing your MAC-6600 with an amp with more PRaT? Maybe you don't have synergy with your cables? Remember a Magnepan needs many hours(500+)for a complete break in!

You need to identify what aspects are contributing to your lack of involvement, otherwise this is just a crapshoot. Is it timing? Is it a lack of tonal richness or image density? Or a lack of dynamics? Involvement may be subjective but that doesn't mean you can't identify what's causing it, and it would make this post much more helpful and productive.