I like Greedo for 4 pts. If he was 3 I'd take him just about every time, even with his Slow on the Draw handicap. At 4 he's an interesting dilemma, but probably worth considering a lot of the time. I'd rather him be slightly too weak than slightly overpowered, though. That's the way it should be for all pieces, IMHO.
But also consider his Accuracy and surge usage: he already has a minimum of 3 Accuracy (1 automatic on his card, and each Green has a minimum of 1 Accuracy), and furthermore, each Green die has a 50% chance of rolling at Surge, which means you have 75% chance of getting that surge, which means that it's often pretty safe to attack at a range of 6.
http://mattyellen.github.io/imperial-assault-calculator/ shows that Greedo has an 86% chance of doing at least 5 damage before defense dice are rolled, so that's a pretty hefty punch for a little 4pt guy. With his 5 Speed he'll be handy for grabbing objectives, and if it's a hotly contested objective, he'll be a good character to commit to that job, since he'll be able to put out some good strike-back damage when he drops, and nobody else can make that happen (Hired Guns don't hit nearly as hard as Greedo does).
It'll be fun to see how he plays out in competition. I'd like to say that he'll be decent, but I guess we'll have to wait and see.