you know, when I first started reading this site more I'd see la9 going at it in some threads and I'd think "wow, what a dick". but as I stuck round and learned a little more about how things really work I came to realize that he was usually spot on about all of the advice.
I think some people just have a confrontational personality, and it might not even be outwardly apparent, but something about the energy makes others want to argue with them.
Overall what I have seen is la9 try to save alot of people time/money/effort and not make bad decisions when it comes to their grow. Afterall, if you are going to do something you might as well do it right.
But, what works for people is how it'll get done, and no one is any less for taking another route. As long as the grow is enjoyable and expectations are not too high one can have alot of fun with their first grows without breaking the bank and striving for ultimate perfection.
Although, once the bug hits that thirst for knowledge and a perfect setup never really does go away.
And to chime in on the subject, of all the forums I read (which is quite a few) KC Brains gets pretty low reviews and people vowing to never go back to them.