Magnepan are my absolute favorite for the money. I just upgraded from 1.7i to 3.7i and couldn’t be happier! The sound is really hard to believe. Unfortunately, unless you have a truly powerful good quality amp, you will be very disappointed. My best friend just received his new LRS Magnepans but is running them with a NAD M32 and the amp just won’t power them.
I don't think Maggies need a high-wattage amp so much as they need an amp with a very robust power supply. I had no problem running Maggies with a 90 watt/ch amp with 72,000 microfarads capacitance and huge EI Core transformer.
The problem with the NAD M32 is its class D topology - a topology which always sounds weaker than the specs suggest. It's why it takes a 1000 watt class D sub to match the grunt of a 500 watt AB sub. I don't know the teachnical reasons for this phenomenon, but IME, class D always sounds/feels about 50% the strength of A or A/B amps.
Back on topic, I find the Maggie .7s are the greatest value of the brand - even preferable to the 1.7i. I much prefer Spatial Audio's open-baffles to the 1.7s, but compared to the .7s, it's a tougher call.