When GM updated the body style on these vehicles they changed the front suspension to a coil over strut design to match the truck's suspension. So now your front lowering options are struts, coils or knuckles with knuckles still being the most popular. Also to note is that some of the Escalade's have the optional Electronic dampening front struts so you can not change them out without causing problems with the electronic ride control.
In the rear the changes from the previous generation are quite mild. No more Premium rear shocks would be the biggest change I can think of. Once again, select your rear lowering coils carefully to get the proper mount of drop.