Odd. I have recently upgraded from ML aeon i's to Vantages and have thought both models as crisp, light, and fast. For a comparison when I originally auditioned the Aeon i's, my other choice, Polk L25's or whatever sounded absolutely muddy compared to the ML's.
The ML's specialty is mid-range clarity but yes, they can be very tempermental in setting up although I feel they are worth the extra time and effort. One thing that is also characteristic of the ML's is that they can take on any improvement or upgrades in head equipment, making perfection even better.