I would think that both would be a good match with the MA's. They are both great with music and fairly neutral sounding. However, there have been some quality issues with the NAD's, so make sure you talk to the dealer first before buying one cause my local dealer doesn't recommend them and they sell them. I think I would go with the Rotel.
rotel seems to have much better quality control(build quality).Also I suspect the performance is much better as well!!!!I would say even if the price of the rotel is up to $500 more I would buy it instead(I say this partly because both receivers are expensive to begin with).If you could get a good price from a local dealer with a good return policy for nad it's worth considering,otherwise get rotel due to better build and performance(plus resale value)which will insure your satisfaction!!