Mixer Mode Internal o external in XDJ-RX2

Good afternoon, I have the new XDJ-RX2 and I have several doubts about its use, using Rekordbox Dj software, which would be the best mode of use, in settings of mixer mode internal or external?

The second would be if it is better to use the rekorbox in export mode with pro link? Or in performance mode.

Thank you..

Angel.