@Jinbeifan1: he used it to keep them contained so he can kill off the espada. But Yamaji could use that time to prep the attack he was gonna use on aizen
Hate to say this but, nobody here used the term great mobility but yourself...
He managed to fight toe-to-toe with the admirals which would mean he is fast enough to keep up with them and dodge their attacks. Even in his weakened state he was able to intercept Kizaru while he was in his light form.
Yamamoto has psudo flight. Psudo being the key word there, in that he can stand and walk on the air but he cannot fly through it. Just because he can walk on air does not make him immune to the air vibrations caused by his quakes, Aokiji was hit by them in mid-air, Yamamoto will not be escaping him just by going into the air.
Nobody said Yamamoto only has his Bankai, I even said he would have a better chance with his Shikai due to its range.
Yamamoto can't tank a quake, and Whitebeard cant tank his flames. It can go either way. And neither is taking it with ease.
Its his Bisento.