Zaraki's own stamina is immense. Nnoitra stabbed and opened him up do many times it wasn't funny but he still one shot him after he got serious for a moment. After that he went on to face Yammy with Byakuya and they won and he was still standing. Zoro migh even be better but it probably won't come down to stamina since its not an area I advantage that is very big. Durability actually goes to Zaraki. He could tank Ichigo's slashes without the slightest effort and receive no damage whatsoever. This is back when Ichigo was only Vice Captain level but when Zoro can take a slash to the body and receive no damage at all even from fodder, then he can compete in durability. That's not all either he caught Nnoitra's big gold cero barehanded as well as Nnoitra's blade. Speed is obvious. Zoro kills him there, but Zaraki is like Whitebeard. He's not a speed type but he doesn't need to be. Nnoitra and Ichigo were considerably faster than himself but he had little trouble working around that. His reactions are much better than his actual speed. Strength is iffy. Zoro has several good feats of strength but Zaraki does too. He parried and overpowered Komamura in their early mini bout and Komamura could overhead lift and throw the likes of Poww who is about 100 meters tall and almost as wide. Zaraki also casually can cut through towers, of course with one arm. And he has a very impressive leveling feat in 503 that Zoro has yet to replicate. It's not nearly as one sided in my opinion as you imply it to be, and i personally believe Zaraki has the advantage. However I'm still saying Zoro could win.