I recently purchased a DJM 2000 and 2 CDJ 2000's, so far everything is absolutely perfect with no issues that i have been reading on here..... except maybe one. Up until now i could only get Traktor to see 2 outputs, no matter what aggregate device combinations i tried it would only see 2 outputs, don't get me wrong it worked fine but the only annoying thing was that Traktor would only output to the same channels on my mixer that my CDJ's were plugged into, meaning there was no possibility for 4 deck mixes/cueing. Anyway today i decided to select 'DJM 2000 output' in the audio settings of Traktor and now i can assign all four decks to any of the 4 channels on my mixer and my CDJ's work how they should, PERFECT!!! The whole Aggregate device crap threw me way off. I'm a very happy bunny now and i hope this helps anyone having the same issues.