Works very well; I have KOMPLETE KONTROL 61 in addition to a KeyLab MKII 61, and with Komplete software, all Arturia synths are quite fully integrated into the control surfaces using NKS. Not as well as the Native Instruments "native" instruments, but that's to be expected (in the same way that Native Instruments instruments aren't integrated into the KeyLab control surfaces as well as Arturia's own).
My only complaint would be that there are sometimes dozens of parameters to page through to 'tweak' Arturia synths on the KONTROL, where it's much easier on the KeyLab because of Arturia's encoders AND sliders (the KONTROL has only encoders). The dual navigation screens on the KONTROL are really nice, but I find myself looking at my monitor just as much as the displays. The keybed on the KONTROL feels better (it's a Fatar with great weight and aftertouch), and the "play along" lights are sometimes useful for figuring out complex patterns, as is the ribbon controller (it would have likely made more sense above the keybed).
Be forewarned though - like Arturia, NI has a funny habit of sending you tempting offers for large bundles and before you know it, you're knee-deep in synths that, while fun, aren't going to be explored to their full potential - preset skimming is common, and all software vendors have figured out upgrades to the point that it's basically an annual subscription.
Right now, I'm having the most fun with a PROGUE (
https://www.jsisynth.com/progue.html) synth that I built, since I'm trying to see how well I can emulate lead and bass synths that I like in the absence of a computer. It's basically a Moog Prodigy and Rogue hybrid, which also can sound like a Taurus.
If you have a specific integration question, please let me know.