I had a pair of 1.6qr and generally speaking the more power the better. The only exception was the BAT VK60 (only 60 watts- $2000 used) which was the best of all of the amps that I tried. Also, I've had success with the Marsh A400 (200 watts) which was significantly better than a Bryston 4BST. Sim amps may be a good choice too, though I've never tried them with the Maggies. I have heard them drive inefficient speakers with power and finesse and they seem to have the right tonal balance for the Maggies.
I've had three NAD amps and two Rotels and while they are very good, I would not use them to drive the Maggies.
I've had three NAD amps and two Rotels and while they are very good, I would not use them to drive the Maggies.