As long as you have a heat efficient build (which differs amongst the various mech building philosophies) it boils down to player skill.
I've seen great players in horrible builds still getting top scores and vice versa. So don't be so bent up over a 'perfect' build, because they don't exist in this game. Find something you are comfortable in and practice, practice, practice.
And remember, don't get discouraged about your builds if they don't fare well in single player pugs, get Teamspeak and start stomping around! Teammates + communication = more success than a '1 man army build'
EDIT: Forgot to add my D (Founders) build; for pugging:
4 ML
Gauss Rifle (4 ammo, can be 3 if you want an extra ton of armor)
2 SRM6 + IV artemis (3 ammo)
S315 engine
560 Armor
*1.43 Heat efficiency (*new HE meter; it's important to be able to fire your weapons consistently as an atlas for any duration of any fight)
Balanced, fun, long range poke and enough armor
People will criticize it for not doing AS MUCH dps as it could be, but once again i say player skill accounts for more than builds do in pugging games, so just have fun with it!
Edited by Black Alexidor, 24 January 2013 - 02:38 PM.