Only backing Kabayel as he is proven at HW, whereas Opetaia isn't. But, I do rate Opetaia highly and I think he will become undisputed CW champion, and I could see him for sure having success at HW. Holyfield, Haye, Usyk have all done it. Would be a great fight.
Kabayel because he is proven at Heavyweight but I like Opetaia. How long will Opetaia stay at Cruiserweight if he is not getting the fights he wants?
Kabayel is a good fighter. Above average power, good but not great movement, good punching variety, can fight off the back foot and front foot, excellent body punching. Good in all areas but except for his body punching, he isn't exceptional in anything. Opetaia is quicker, a southpaw and IMO likely hits harder. But Opetaia is not proven at heavyweight and his cruiserweight competition hasn't been stellar except Breidis. So at the moment, i can't favour him over Kabayel. But in the long run, IMO he has a good chance at heavyweight if he can tighten up his defense.