@Neils > I'm happy to try and answer as many of these questions as I can for you..
1) Yes! It does have emergency loop. ( See pg. 13 of the manual.)
2) The faders are nice and smooth, more like the 850 than the 250.
3) If I recall, they're slightly smaller than a CDJ-2000, but larger than the CDJ-350.
4) Yes! ( See FAQ #2.)
5) I'd say it's as good as the top-level players.
6) I don't believe it has the same D/A converters as the DJM900 series, but would expect it to be more along the lines of the DJM850 quality of audio.
7) I'm not sure how it compares to the 2000 or 2000nexus, but it is quite good.