hifidream,
Congrats on choosing to drive your 20.1 Magnepans utilizing 2 class D Benchmark AHB2 amps (one for highs and one for lows with an active crossover). What a great combination!
Excellent speakers driven by excellent amps, no wonder you and your father are so pleased with the results. It seems like you have become, as I have, a very pleased user of class D amps driving Magnepans.
Class D amps driving Magnepans, and likely many other speakers that require substantial power for best results, are such a good match that I'd suggest that anyone looking for new amplification should audition a good class D amp before purchasing anything else.
Enjoy,
Tim