The crit up is meh. 86 and 88 already have crit chance through the roof with an HK lead and their own abilities. This doesn't help a Droid team that much, IMO.
The major improvement is speed, so that 86 or 88 will be difficult to take out before POE/POGGLE act. But JE doesn't have a taunt. So he's not all that. Poggle O Up is way better than crit up. Poe taunt + expose (negative status effect for 88) is better than crit up. JE is a compromise. I'm actually disappointed and I don't think he will be a game changer.
I'd really have to see how he plays out. I like that there will be increased variety in droid teams. There are already a few useful combos. With JE, there will be more than half a dozen special purpose droid teams, I imagine.
I think JE will be useful with Poe or RG, in place of Poggle. This means the droids will have increased survivability but do less DPS. And it will make JE's revive potentially come into play.