I too ran it with static difficulty for both ranged and melee/brawl and it worked really well so far.
I'm thinking Jedi/Sith combat will have lots of talents giving upgrades, increasing difficulty, etc. If I go opposed now that means I'm using purple/red for competent fighters not counting any possible talents.
The only real close combat spec we're seeing now is Marauder with high soak/wound and damage output. I'm sure we're gonna see more specs, e.g. a rebel agent trained in martial arts and finally force traditions combat specs.
The Forsaken Jedi in Adversaries is already using Dodge 2. If we go with opposed rolls anyone attacking him will get 5 red dice to the attack pool. Question is do we want that? I'm not sure, so I'm sticking with static + modifiers.