Should I sell my last zoom and go all prime?

Hello

I've been some kind of semi-pro and photojournalist for a while. I thought I need to cover all the focal lenghts. So I got Tokina 11-16mm, Nikon 16-85mm and Sigma 70-200mm OS with D7000. I had also (and still have) Nikon 50mm and Tokina 100mm macro.

Then I sold D7000 and the dx lenses. Bought D600 and Nikon 20mm f2.8 and 28mm f1.8. Now I have temptation to get rid of the Sigma and buy Nikon 180mm f2.8 and maybe 300mm f4. Those lenses got no image stabilation and AF is maybe worse than with the new Sigma.

Right now I am mostly photographing bands, portaits and artsy stuff. No sports or news for example so much anymore.

Is this interest in primes only emotional or is there some idea? Should I instead maybe just keep the Sigma (it's nice but not so much wide open in the long end) or maybe consider the new Nikon 70-200 f4? Or somerhing else?

Please tell your opinion!

- Iisakki (from Finland and new member for this forum)