Steveashe, good to know the M30.1 has worked out for you. The 30.1 certainly does not go too deep in the bass, reaching down to 50 Hz on paper which in my book is inadequate. Although my current Marten Dukes go down to 38 Hz, I still added a sub to the speakers. I am happy to report that the integration of the sub in my system is quite seamless as well.
I attribute the successful implementation to 2 main factors - positioning of the sub which is of utmost importance, and secondly, isolating the sub with proper isolation product. Placing the sub on spikes or directly on the floor without spikes is a rather serious compromise as I have just found.