The one thing Bush can do, and it's debatable if the other RBs on the Dolphins can do this, is take it to the house if he's in front of the pack, including outrun a db that might have a bit of an angle on him in pursuit. Miami, IMO, needs an every-down back that can take it to the house if he breaks through the line clean.
I think this trait of Bush is underrated by Dol-fans and most posters on this board.
Also, I think that for every run where Bush's 'dancing' might've cost him a few yards instead of just punching it up in there for a 2-yard gain, there were 3 other runs where that 'dancing' enabled him to find or even make a hole (by getting defenders out of position) and burst through for a 10+ yard gain.
Reggie Bush, with sheer speedburst, could get through a tiny crack in line and be on his way. Another back would try and use his power to get through that hole and might only gain 4 yards because the LB or DB would get over there and cut him off once he got through the line.
I think Reggie Bush is better than most think and with just a little better blocking could produce a monster season. His numbers, IMO, don't represent how good he is and I'd hate to see us wind up being worse without him.