Guys this is not the point. Yes there are many other level editors and modelling applications, but none of them can beat the established Valve Hammer or 3D World Studio editing. It is fast, simple, accurate and most importantly FUN. Your creativity is lost when you have to switch between applications and constantly re-import your assets. This is why I bought Leadwerks in the first place- it combines level editing and Lua scripting in one coherently designed package.
My only wish is they re-implement full CSG tool set from 3DWS.
[Edit]
I personally never liked SketchUp.