People say Vector needed more screen time, but from what I recall from the manga he didn't appear all that often there - he's a power broker kind of guy, being inaccessible by default comes with the territory. The movie was actually generous in the screen time it gave him, unless I'm forgetting something about the manga after all these years.
The way they handled Kinuba though was kind of a testament for the adaptation work put into this to help streamline the movie - in the original he was into arena combat, not Motorball (which was introduced later in the story), and Makaku takes over his whole body directly, while in the movie that acquisition gets to show Hugo at work and how Vector deals with unexpected interference in his plans in particular, and how merit and ingenuity alone won't ensure success in that setting ("no one is greater than the game").
And then there's all the fans using t-shirts with his name and number, which hint at the kind of hope the character likely represented, even by the time he was out of commission.
I don't recall Kinuba being in the OVA, so that was a neat surprise to see how such a minor manga character got used.
I also kinda loved the implication that Ido contributed indirectly to keep the streets safe by giving hunter-warriors free repairs - in a society that's clearly pushed into savagely competitive mindset for the benefit of higher powers, it was a neat touch seeing that kind of small but important bit of mutual aid being hinted at.
The whole bar sequence, up to the exit from the bar, really is kind of a nice microcosm of all of the movie's weaknesses (corny lines) and strengths (neat bits of dialog and great action).
It kinda help but by then Alita/Rally is wearing something that more closely resembles her classic manga self, something that progresses neatly throughout the movie.
Not sure if I'll go watch again today... There's a bit of a movement online about this, but I really want to help this movie to get a sequel or more, the TUNED/Barjack arc on the big screen would be amazing (I wonder if James Cameron could get George Miller to direct that...)