Itch was meant to be something totally different than Traktor - Itch is lent heavily towards the traditional TT paradigm, that’s why Itch is (controller-wise) one of the best emulation of this paradigm available…
But now Serato is moving Itch into the direction of Traktor Pro… I’m really curious how this will work out 
Got my vci-300 today and so far I LOVE IT! I have a vci-100 and traktor 1.2 and I really like that setup but I was looking for something that felt more like turntables. this thing is perfect. I might keep Traktor and use it with my Oxygen and just get rid of the VCI-100. If the VCI-100 was 14-bit midi and cic scratches in next to real time I would be 100% on the 100. Unfortunately the latency was to much for me 
Theres bound to be a mapping from A&H but i can guarantee that NI will not be making a mapping for it.
Regardless, it will be very easy to map for Traktor, probably easier than for Itch.