ps. Sorry my bad english 
ps. Sorry my bad english 
Do you want a brain?
...
But seriously, I have a point: why spend so much time planning when good old trial and error in hammer works just as fast, and is twice as fun?
The only plans I've done of maps (as I've said many times before) are little sketches on paper that take about 30 seconds each because as soon as I get the idea I don't want to waste any time putting it on paper, I want to get it into hammer and test it as fast as posible. (having said that, no one has yet seen the fruits of my labour as far as mapping for portal goes)
also. i never plan ANY of my maps (on paper atleast) i think of a general idea. and then go to work on it in hammer (or previously WorldCraft) and then hammer it out (pun intended) 'till it looks good.
ofcourse you can edit idea if you like and make it better and watch What comes out.. ;P