I have him at lvl 74 7* G9 plus one piece, still missing 100 stun cuffs and 50 stun guns to fill out his available gear 9 slots. I run him an a droid aoe crit team. HK 74 7* G8 Max (no pre crafted items) lead, 88 74 7* G8 Max, 100, Phasma 74 7* G8, RG 74 5* G8 Max.
High HP team with tanks toons and a glass cannon. The HK lead gives turn meter on crits and all three droids do aoes. Phasma gives advantage and the droids get multiple crits on each aoe filling turn meter and allowing them to go twice a lot. Royal Guard there to try to stop 88 from getting taken out too soon.
IG-100 is pretty good now. I have used him in a few different droid teams. High Hp, decent counter chance, turn meter reduction on aoe. Damage isn't high, but it is not bad. He gets speed up if left alone for a round and offense up if left alone for another round. With HK lead with turn meter on crit, he gets to go twice a lot, giving himself a buff right away. He spends most of the match with speed up and offense up. His speed is very low, but with the speed up and turn meter gains he is deceptively fast and goes twice a lot. He can also crit on his counter and gain turn meter with HK lead.
I need to do more testing with him in various comps. I have only really use him with HK lead. He is definitely improved and fits better in this meta than he did previously.