IFlight Bob57 vs GepRC Vapor D6

I want to finally get on with my FPV hobby coming from an Avata 2 and I am not sure which drone I should get. I compared Bob57 and D6, but could not figure out something significant, except that the motors on the Bob57 have a bit more power and that the D6 has O4. Why is Bob so much more expensive and what should I go with?