You asked about Midi control…
If you are using time-code discs in your CDJ’s with the rest of the deck midi-mapped, both programs perform very well.
…the big question is really the jog-wheel.
White it is known that Serato does not support direct midi-mapping of the deck control to jog-wheels, Serato does have one advantage over Traktor and that the CDJ has been christened with Advanced-HID support, something that Traktor has yet to implement despite the massive requests for it over the years. You can map your jog-wheel in Traktor but the response is very poor. The Pioneer CDJs are considered Native controllers for Serato (jog-wheel control is unlocked for that device only when serato recognizes that its connected) , in Using Advanced-HID mode on the deck with Serato you can forgo the time-code disc and achieve extremely tight deck response. The caveat is that the entire deck has a pre-set mapping that cannot be changed in this mode.
If you don’t need to buy a mixer the price difference is roughly $150 between the Traktor Scratch A6 soundcard and Rane SL2 for serato.
Have you tried either or other DJ software before?
What do you like?
What do your colleagues use?