I use iTunes to sort my playlists out for Traktor. I have all my music for work and DJing in iTunes, but I use the genre to identify what type of music it is and if it’s usable for DJing, then simply create smart playlists that will only import what the parameters I’ve told it to search for into that playlist. I know people that do it for BPM as well. Eg 80-90 BPM smart playlist will only import 80-90 BPM tracks, then when you open Traktor all your playlists open too.
But once again it comes down to your own preference, I use it because everything in my house is Apple, with iCloud and itunes match etc. It also suites me because i play across 3 or 4 genres/ bpms so it’s quick and easy for me to be super organised to access all my DJ tracks.