I, for one, like to focus on Grunt choices ahead of Elites. Sure, some elites are the bomb-diggety when it comes to certain situations, (CC, Channeling, lots of shooty doom), Grunts will give you a decided advantage in that you're gonna have alot of feet on the ground, each of which (in most Corp armies, Wolf Pack nonewithstadning) has an assault rifle.) The ability to lay down fire to 36', while moving 4 inches (in the case of Light Infantry equivilants) is pretty powerful. That, and I can have a Capitol Heavy Infantry army with things like Snipers and RL specialists, and give my squads tactical flexibility (Anti-Armor, anti Special Character, etc.) I'd much rather duke it out with a smallish squad of Elites then a full squad of grunts out in the open. (Doubly so for Grunts with SMGs... nasty nasty things, those. Imperial IDC Gendairmes for example. SMGs, with specialists with HMGs. I doubt many Elites can stand up to that when they get within 6-12')
Elites are mostly good for certain situations. Have a tavle with Environmental effects? Take Sea Lions and ACG. Fighting in close confines? Sunset Strikers or Assault Marines are good for that, and so are Free Marines. Need to take/blow up an objective? Rangers lead the way, literally.
So really, you want Grunts to deal damage and soak up casualties, Elites to win objectives/optimize your force for a certain situation, and support choices to lay the smackdown.