Official comment
I don't know what you guys are complaining about... when the XDJ-RX was introduced, it was marketed and sold as a stand-alone product, where rekordbox was only used with it for exporting music to USB devices, or linked to act as a media host.
rekordbox DJ was introduced and all the XDJ-RX users were up in arms that their unit was not in the supported hardware list. It was originally never going to be supported as the intention for the XDJ-RX was to be used without a computer. Due to popular demand, the XDJ-RX was included with basic MIDI support. But apparently that wasn't enough because users complained that the lovely screen on the XDJ-RX was "useless" and that it was a waste to use it with rekordbox DJ because they couldn't see anything on it. So the product team and rekordbox engineers agreed that they would incorporate HID functionality -- something that only months prior they said they would not invest the time or money in doing. And when they finally release the 2.0 firmware and support for the XDJ-RX in rekordbox DJ 4.0.8 what is the reception? A bunch of pissed-off users who want to roll back to 1.8.
If you want fully functional waveforms, use a USB drive or the link.
If you want to use your XDJ-RX as a controller for rekordbox DJ, you simply won't have the same display; you get browsing track detail on screen and overview waveforms along with the time and position information.
