Chair and Komplete Kontrol. I am not sure about Komplete Kontrol. I will probably get one. Chair I will definitely get. Last weekend went planning my home studio. I played with software instruments I had. Good portion of them are NKS-ready. Not all though. Pre-mapping would be nice to everything but it is not the reason why I want Komplete Kontrol. I can easily get mappings to Push 2 (in picture above) which I am keeping. Lights and scales are reasons I want Komplete Kontrol. Everything else is additional.
I am starting to use Kontakt more which have key switches in many instruments and some instruments use only part of the keyboard. Having lights showing which keys are key switches and which are at audio range of the instruments makes playing easier. Push 2 is good but it isn't very good with key switches when you play with scales and for some instruments old fashion keyboard works better. I have pretty good midi key board which works well as Ableton Live controller. I used it before I got Push and later Push 2. It would work well but it doesn't have the lights.
Komplete Kontrol has scales which makes it better than regular keyboards. I am not keyboard player. I can play keyboards but I am not too familiar with music theories. I'd like to do music in other scales than C major too. Having scales help. It is my favorite feature of Push 2. I would like to have same on keyboard too. I could of course use Push 2 as indicator if note is on scale song is on but that is not as easy as having scale on your keyboard.
I am planning to add more software instruments to my music. Komplete Kontrol would help that. But new chair would help more. My current chair is not that good. I need something I could sit for hours without problems. Little reorganization of home studio is needed too. That is probably best thing I could do for my music. I am starting to think I already have too many synths. Both software and hardware. Having ergonomic studio with instruments I use most easily available would help me more than new instruments.
I am really bad selling anything. I need to find some place for everything after I decide what I will have easily available.