As someone totally unfamiliar with their NJPW work, they seem incredibly boring to me. They're basically The Ascension without the paint.
I'm assuming they were better in Japan.
Karl was better to a point. Gallows was never much. The whole BC was cool in the beginning because Balor was a beloved babyface who turned quite unexpectedly and Karl was a respected singles performer. Their tag team run was fine at best and mediocre at worst. They had far more creative freedom and better opponents over there as well.
AJ has survived because he is an unbelievable in ring performer but isn't much else besides. I never understood the signing of all three of them from day 1 tbh. Seems more to disrupt NJPW than anything and cover their inability to create main event stars or at leaSt believable threats to Roman.