The simple truth here is that Weezys speed is sufficient enough to kill most people once hes actually behind you. The way Weezys got behind nub was not with speed but with a roll which put him on nubs tail and from there it is too difficult to shake a player with that caliber of speed and stalls.
I just realized rockstar also changed front camera. Back then you could see much more. Look at this then go dogfight now. I think they fucked with front camera last year