We use the Saga edition, with a few tweaks. Mostly taken from either the former edition or DnD 4E. Here is a summary of the most important changes:

• There are 30 levels instead of 20.
• You get a level bonus every other level (to attack, skills, defense).
• At odd levels you get a feat.
• You also get cool stuff at every level from your class; non-Jedi alternate between bonus feats and talents, Jedi between bonus feats, talents and force powers.
• You get fixed hp (vitality) every level; you don't roll. For Jedi it's 5/level (x6 at 1st level).
• There are also some changes to some skills (including 3 Force skills rather than 1), feat and talents.
• There are a lot of changes to Force powers (they are more powerful).
• Jedi are more powerful than non-Jedi; but they are (apparently not applicable to E'tan) bound by the Jedi Code.
• Using the Force is either skill-based (i.e. lifting a big rock is Alter-based vs. difficulty, lifting another Jedi is Alter vs. Control) or work as any other attack (Force Push or Lightsaber Throw for example)
• Attacks are either STR-based (melee), DEX-based (lightsabers and blasters) or CHA-based (Force)
• Armor provides DR.
• Some changes to the way vitality/healing surges etc. work.
• Force points work differently; they regenerate regularly and can be spent in more ways.
• Destiny points can also be used more creatively.

There are probably some additional changes, but these are the most important ones.