I love's me brawling.
After brawling last night, I did not do too badly, but one of my goals in a game is simply not to get killed for the entire game.
Period.
Brawling causes too much risk. Sure you have big guns, and you can get a LOT of kills doing it (I had 11 kills 3 deaths in brawlers) but the risk is too much unless you have a coordinated teammates to work with.
What I find happening when you brawl is that, the better the brawler you are in, the more damage you attract.
When in a Warhammer I found that people were ignoring me somewhat, and I actually did better in the Warhammer than I did in the Mauler Ac20 or Atlas AC20 versions.
When I was in the Mauler/Atlas people simply put too much fire power against me to accomplish the goals that needed to be done (IE killing enemy mechs). Now, if everyone on my team had had maulers/atlas's it would have been different, but from an operational standpoint the Atlas and Mauler are simply too big, too slow, to make the best brawling mechs in an offensive capacity. I could see them working as a semi static defending mech, or as a part of a much larger force, but as the center of a mixed force of lights, mediums, heavy and assault mechs it is not the best set of mechs to attack with as it just causes too much focused fire.