Originally posted by ChristianRock Knowing what field of professional photography would help...
This!
If you are in need of a fast camera the K-1 is to be ruled out. And fast is depending on how you work as well. While the K-1 is praised by landscape photographers and depised by those working in sports, wedding photographers have split views. Some pray it as a very ergonomic tool, some say it is still to slow when things get hectic.
It would suggest, search the internet and youtube, you get al lot of enlighting information about the K-1 especially.
Also I am a proud owner of a K-70, I would never use the camera as a pro, because the operation is mainly via the screen, which really slows you down. If you are going pro I would go for the camera with the best ergonomics which (beside the K-1) is the K-3. K-3 iii or the K-3ii would be my first choice.
Only if you really need a tiltable screen you should look at the K-1 and the KP.