Hey John
I can't remember whether I opened my M3s or not. But, I had to smile when I read TomDP's recollection of the first time he listened to a pair of M3s. My first Axiom speakers were a pair of M3s after the effects of reading positive review after positive review about these speakers had finally had their effect. At the time I was running a pair of Infinity Overture 3 speakers ... I think the "3" stood for $3,000. Anyway, I hooked the M3s to a modest Technics SADX 940 HT receiver (using only 2 channels and a sub) and was blown away.
All in all, the M3Tis sounded better than the Infinity Overture 3's. I sold the Infinities and the Infinty RS3 surrounds and center and never looked back.
The M3Tis are my personal favorite Axiom speaker. I should grab another pair and swap out the standard capacitor and resistor, replace them with some nice Jensen paper/oils and Caddock or Mills resistors, and see if that cures the ever so slight grain that separated the M3s from ultra high achieving bookshelf speakers.