the fact that you get the buildings not loading fast enought for you might be that you have the draw distance set too low (which can only be adjusted in single player)
or that your system isnt handling the extra stress MTA is putting on your graphics card/cpu and it just cant handle the scenery streaming in so quickly.
i suggest you turn down your resolution, max out your draw distance, and make sure you dont have a lot of background processes running.
As far as others being able to jerk ahead of you, could be lag, could be that you get sudden and quick drops in fps that only last a split second.