Arc trooper how good is he?

I'm planning on leveling up my 501st squad and arc trooper is the only toon currently sitting at 5 stars. Of all the other clones he doesnt come off as the most impressive. Sure he can summon a blaster turret and has 2 abilities that purely focus around said summoned weapon but since this turret cannot be used in raids and other specified areas he doesnt seem to have much to offer if he cant use his primary ability of summoning. Sure his basic attack is ok but aside from the other 501st clones he seems like a pushover. I'm not trying to bash the toon it just seems that other toons like mon mothma and geo brood alpha who also have summoning skills have way more abilities to use outside of just focusing on the ally they summon.