We won't be able to tell from merely the first film. He needs a lot more tie in material, and we need to see what he's capable of in terms of dueling/force power. But I think he'll be a lot better than our initial thoughts of him being "Inquisitor" tier or whatever nonsense some of the older posts said. Given his lineage I think we can expect some great showings in the years to come, and hopefully Marvel gets off their asses/Storygroup releases his own eponymous comic series or novel pertaining to him