hi nu.why?
1.legendary newtype amuro ray(the greatest of all gundam pilot)
2.hi nu got bazookas,beam rifle,and fin funnel.
3.more experienced in mobile suit battle.
If you asked me a few months earlier I would say OO is weaker but if you talk about technological and historically speaking Hi Nu cannot fight against OO. Why? OO can form a giant airship sized beam sabre, the GN particles can trash Electromagnetic waves all over the place and don't forget, Hi Nu can't trans-am.
Also relatively speaking we are talking about different time eras and different universes. If you put the GN drive into Hi Nu then there maybe a fight but against OO he can destroy everything.
Actually, my vote goes to the 00 Raiser simply because of Trans Am Burst, which cancels out the Hi-Nu Gundam's Fin Funnels. Next, it also has its ability to quantize, not to mention its superior weaponry...