I don't know a lot about the 850s so my information is via google and may be wrong.
Just before I start, let me give you a quick background on my thoughts/experiences. I have CDJ900s that are networked to Rekordbox via ethernet, I browse and play all my music straight from the CDJs (which is the whole reason I bought CDJ900s and sold my CDJ400s, using CDs and USB for tracks is really annoying. Being able to browse everything from the CDJ is awesome, everything just works without me needing to mess around.
When I lived in NL I bought a cheap Numark controller and used it with Serato, which was my first experience with that type of DJ software. Having the detailed waveforms etc is sometimes useful but personally, I much prefer Rekordbox for a few reasons:
- I have my music organised in iTunes with smart playlists etc, Rekordbox syncs seamlessly with that. Serato had a bit of trouble, it wasn't nearly as polished. For example the track order in playlists would be wrong in Serato, which was annoying if I had sorted the playlist in a specific manner (eg organised tracks from softer to harder, etc). Rekordbox displayed the track order the same as in iTunes
- I find DJ software like Serato/Traktor/Rekordbox DJ makes you lazy because you end up looking at waveforms, BPM counters, using sync etc. I personally prefer to DJ the old way. Sure, you can do things you can't do with pure CDJs but my approach to DJing is that I don't do anything I couldn't do in a club with CDJs/1200s and a mixer... so that means learning to use the looping on CDJs rather than using quantized ones in Serato
- Rekordbox is great for exporting to USB when you want to play in a club etc... 99% of clubs have Pioneer equipment so its easy to just export to USB from Rekordbox. And imo there's no need to take a laptop to a club unless you are using full DVS with turntables. Clubs usually have CDJ2000s which display the same waveform info as a laptop.
- Using traktor with a CDJ seems like overkill, imo you'd be better off selling the CDJs and mixer and using a controller instead (unless you specifically need the CD functionality or you have turntables running into the mixer). Now that controllers are so common I don't see the point in buying expensive CDJs just to run DJ software. For the cost of CDJs and a mixer you can get some amazing controllers.
So what I found after my research:
Rekordbox DJ (costs $129AU) will work with the CDJ 850 - note that Rekordbox DJ is different to just Rekordbox. I use an old version of Rekordbox (3.3.0) because Pioneer are now making you pay for Rekordbox DJ in order to play your music straight from the PC to the CDJs.
Traktor Pro 2 (costs $159AU) will also work with 850s, there is even a user guide on the Pioneer website showing how to set it up
I haven't used either software so it would come down to your preference and budget, they have similar features. They both have free trials so maybe test them out and see which one you like better. Traktor has been around a long time, it's compatible with hardware other than the CDJs, it probably has better features than Rekordbox DJ but it depends if you would use them. Rekordbox DJ probably works better with the CDJs, the music management is better imo, plus you can then just export straight to USB when you want to play in a club. Using Traktor means you might still need to have Rekordbox installed so you can export to USB when necessary.
I'd probably go for Rekordbox DJ but that's my preference
LOL just saw the OP's post date. Wow I just wasted a lot of typing