Arms will not change the height
long arms have less rotation during articulation, so less sway bar effect. So easier articulation and less highway sway bar effect.
The longer arms also reduce the brake anti-dive by shifting the brake torque force further back in the chassis.
You get less caster swing as the suspension cycles with long arms.
Long arms have less roll steer due to less wheelbase change as the suspension cycles. Short arms running a steeper angle have more wheelbase change and more roll steer, but if you have level short arms (drop radius arm brackets with a lift) there is less roll steer.
Long arms can get into breakover angle as the mounting point is further back on the chassis.
Long arms have caster correction built in, less bushing needed. But you can get into U-joint binding easier with long arms as the lack of caster swing makes the U-joint at the front pinion operate at a steeper angle as the suspension droops.
So as much as people love there long arms, they are not a fix for everything. There are true benefits, and if that is all you are after and can put blinders to the negatives they are the greatest thing ever. Some people will just claim them the greatest simply to justify to themselves the expense they put into them. I find them a bit pointless into a mild trail truck or a street truck.
