Anyone compared Sanders Magtech vs. McIntosh MC462/52 or MC611/01 with Magnepan 3.7/20.7?

I know a lot has been written about all of these amps with the 3.7 and 20.7 series Mangepan's, but I was wondering if anyone has done a direct comparison and can describe the differences in what they heard?

Yes, I know, the best way is to demo them myself, and I will be this coming October... but until then, I would be interested in getting other's opinions to prepare myself for certain things to listen for, think about, etc.

Contrary to all of the popular opinions out there on the net that you needs gobs and gobs of watts to make the Magnepan's sound good, that is not my total experience. I have a new pair of 3.7i's (one month old) and am running them off of the 8 ohm tap of a McIntosh 6700 integrated 200 wpc amp. It actually sounds fantastic with plenty of warm bass, and depending on recording, can be chest pounding - from either vinyl or digital. My audiophile jazz recordings with piano, guitar, vocal, drums, and upright bass are the most accurate (compared to a live jazz club) I've heard.

The issue is, I have to turn it up to a volume that would be similar to what you would hear live - which is fine when in the mood, but at times I would like to listen at a lesser volume. There seems to be a certain volume threshold that when crossed over, the speakers open up and do their magic / crossed under, they all of a sudden lose their good charms - dynamics and bass all but disappear. 

So, from what I've read, what I'm experiencing is from lack of proper wattage from the power amp, thus I'm on the upgrade path - I'm sure any of the above amps (in the title) would be an improvement as the least of them is more than doubling my current wattage - but I'm curious if anyone has compared any of these amps paired with the Magnepan's. If so, do they improve dynamics and bass? What did you like about one and not the other and vice versa, etc.? 

Thanks and looking forward to hearing your opinions --cheers!

Jimmy