I get what OP means. I also wonder the same thing. He seems to be one those characters that shine when fully pimped, but before that there are better options. I know I ain't replacing RG with him anytime soon, but then again I'm around 200th in the Arena. Feels like everyone who posts here is top 10 in their shards :)
Also he isn't useful outside arena as he is cannon fodder. But that might change with Wedge's leader ability. Healing on crits helps him last longer. In raids his taunt is useless for me, as the team I use with him doesn't buff much, so Rancor doesn't use his roar (dispel) until Han taunts. Rancor likes to focus on him, so if Han doesn't taunt it kills him and if he does, he gets dispelled.