I am going off of the Stereophile review for the piece. I compared it to my system but it's really not a fair comparison. My two channel system costs $150,000. My pre-amp alone costs $19,000 so I wouldn't expect the Integra to compete with it.
I do have to say though that I think the two channel sound is better than my old Sunfire Grand III. I think in part it has to do with the fact that the integra uses the Audyssey system to correct the acoustic problems in the room
At the end of the day, and this is just my opinion, I don't think the quality of the resistors, capacitors, etc matters quite as much with movie soundtracks as it does with two channel audio. The more expensive units put higher quality components like that into their units because they know people are using them for two channel.
I think in your case though that the Integra, with the right amp, might be an upgrade over the NAD. I would do a google search for the Stereophile review of the Integra.