Jet Pack makes a return in Halo 4. The Jet Pack has been toned down a little bit. It recharges much faster but doesn't last as long when jet packing. It won't allow you to reach quite as high as you used to be it is much more effective cushioning your fall or for hopping across many long gaps to get a better position.
While this may seem limiting in some respects, it can also be helpful. To begin with, it makes the jet pack easier to manage for newer players since you are less likely to get into a position where you can't save yourself. While it might be harder to get the drop on an enemy vertically, it is still far from impossible (except at the most extreme heights) while making the Jet Pack fantastic for short cuts.
