This is the hardest decision I have had to make in my 15+ years as an audio hobbyist.
The HK has alot more future proofing built into it but the NAD could have a cleaner sound for my 2 channel listening. I listen to my CD's alot more than watching DVD's. I know that HK is conservative in their power just like NAD but is there a difference in the quality of parts between these two receivers?
This will take some time to sort out.
I give the edge to the NAD because the 742 has the same pre/pro section as its bigger brothers (same tuner, too). You won't find that on the H/K, much as I like the H/K. Also, the NAD definitely has a better power supply, enabling it to be capable of driving a 2 ohm load. While you don't have 2 ohm speakers, it does mean the NAD has more headroom in the amp section.
Head to head, the NAD is cleaner sounding, as well.