Well, the brief encounter I had with SAGA (two campaigns that lasted about 3 sessions) seemed to indicated Jedi could easily get a super-high "Use the Force" skill that made it really easy to dominate encounters. My character, a Cerean, had a +12 UTF skill, Force Slam and Move Object. Most encounters I was involved with ended before others got to go - I either knocked the enemies silly or pinned them under crates and such. And that was just combat - out of combat I was a pretty good diplomat. If this doesn't bear out in the long run, I'll certainly concede the point.
To continue Pukunui's excellent points, the way Saga assigns and stats Force Powers means that your character had, via his single use of Force Slam, the rough equivalent of one grenade he could toss per combat (with the neat side effect of sometimes knocking people over, but a severe limitation on range). If he wanted more of them, he'd need to spend additional feats to pick up more uses of Force Slam, or spend talents on abilities that let you add another use to your suite, etc.
Since even fairly low-level stormtroopers come equipped with grenades, the non-Jedi characters could reasonably be expected to toss a few of their own in each battle, as well - assuming the enemy didn't throw them already!
Another issue that arises, especially in less-experienced groups, is allowing certain powers, especially Move Object, to do too much. Move Object is not general-purpose telekinesis. You can't use it, for example, to immobilize someone completely, or to pull a weapon out of their hand and shoot them with it. Your comment about "pinning people under crates" sounds like just such an occasion. Yes, it's possible to get people trapped under things, but there's rules on how to escape, and how big the object has to be in order for this to work, etc.
I'd love to be able to run a game with one jedi (maybe two - master + apprentice) and the rest of the players being clones/support characters and it be balanced and fun for everyone -and I'd love to know which system would handle it the best.
I don't think there is one, unless you set it up in an
Ars Magica sort of troupe-based fashion, where everyone takes turns playing the "stars of the show."
The thing that I like about Saga is that it tried, however successfully or not one wants to argue, to make a 7th-level character roughly equivalent with a 7th-level character. Jedi, then, are just much more likely than soldiers or shopkeepers to make it to 7th-level - giving the power gaps we see in the movie. In a major-character-on-major-character fight, though (e.g., Obi-wan vs. Jango), there's no clearly superior combatant, merely different styles.
EDIT:
And, to address the OP's question, Saga's my favorite SW system. However, that has to be caveated with the admission that I've never really played d6 extensively, and the few times I did play I was "forced" to use the Archetype method of character generation (such that, for the longest time, I thought that's how the rules required you to create characters), so I don't have a good basis of comparison there. Saga beats the earlier d20 versions easily, however.
