I got my s4 for over 2 years now. Still, very satisfied of this great piece of hardware !
I made my own tsi (midi map) a few months after I bought the S4.
I still run the 2.0.3 version of TP2 (I am a road (wedding) DJ, so no need for sample decks and others remix-features witch came with the newer versions of the software. Also, had no problem whatsoever with the software, never let me down. I read on the NI forum there seem to be several issues considering the latest upgrades. So, I stick to 2.0.3. If it's not broken, no need to fix it for me ).
About the Kontrol S4:
I know there are certain things that can't be done (in version 2.0.3 of TP2) like: mapping the Filter knobs and Loop size display when using a custom-made midi map.
But also I've noticed (already noticed it 2 years ago, when I made the midi mapping) that the LOAD cue can't be set to a yellow LED on the controller ?
Is there a way to get a yellow LED for the LOAD cue on the controller ?
(I've also noticed that in the Preferences/Traktor Kontrol S4/Jog Wheel, when I check the box (so I disable the Jog Wheel push), it doesn't effect the behavior of the jog wheel platter. It still stops when pushed, when using my own midi mapping. It does seem to work when using the Default (factory) midi map.)