The reason why some editors like the current unreal editor are so popular is because they do alot of the work for you. Now, while in netradiant you can get most of that work done, it takes alot of learning to do so, a year or more (after 3 years of using netradiant I just recently learned how to use the clipping tool.)
One way to reduce this time is to add more primitives to netradiant.
The brush primitive code (like prism, cone, etc) is in:
NetRadiant/radiant/brushmanip.cpp
This works by cutting planes through the "box" you make w/the brush.
Some ideas: http://en.wikipedia.org/wiki/Dual_polyhedron
http://en.wikipedia.org/wiki/Elongated_ ... al_pyramid
(looks like a crystal)
etc
Also, an extrude command would be cool for netradiant
