I've only heard once or twice people talking highly of NT. Care to go into more depth?
NT was originally designed along the lines of a microkernel though in NT 4 they violated the rules and put the graphics driver in ring 0 (iirc) and didn't undo that until around Vista, I believe.
Technology-wise, Windows NT and it's APIs is well developed and designed.
If your biggest innovation of a decade is a carbon copy of a feature introduced in NT 3.5 in 1994 AND THEN it turns out most serious people disable it because you cannot even copy a feature without introducing new vulnerabilities - that's a sign of quality.