ejspain I had your exact amplifier. Was driving Theos speakers mains and LRS surrounds which MAXXED that amp out. Faithful. Never a hint of trouble and I loved it. In my opinion, do not upgrade until you are ready to REALLY upgrade. With that said, I currently use M1200s for my Montis fronts and it really is no comparison. You can hear the panel being driven effortlessly with no cap.
Yes they are a hybrid Class D and Tube amp. I had m700s (still running my center on one) and they were very good but were much more neutral sounding. I can only imagine the 1200s are even better and have a bit more 'life' to them with the tube. I've heard its a night and day difference but I have not yet had a chance to listen to M1200s.
I’m running a McIntosh tube preamp into a McIntosh solid-state power amp. I actually wish it was just a tad bit brighter than it is. But vocals are sublime. I may do some tube rolling in the preamp to see if I can add a touch more sparkle. I auditioned the MA352 hybrid tube integrated, the MC152, and the MC462, and as I went up the wattage scale, the 11A’s revealed more and more detail. I bought the MC462.