The AVS' compatability is ridiculously well done. VRC6 works, Famicom Disk System works, Family BASIC and all accessories required work. Hell, you can load Excitebike tracks with a tape deck using the AVS.
The only thing I havent tried is a genuine copy of Lagrange Point, which has that FM synth chip in it.
I don't know if the NT will do those things, but as it stands my opinion is that the AVS is the best hardware clone ever made.