So in short it is better to use on the Assault mechs and your playstyle. No surrender no retreat i mean why need JJ to retreat then? Use it to jump behind enemies to perform strikes? I am no ninja. But can see the need yesterday when tried on a 3 skull mission and ended up with commander and one other pilot in sick bay for 94 days. Back to 2,5 now until can get my hands on a second heavy. Thank you will try out.
Jump jets let you move in any direction, land with any facing, and navigate any terrain, and they give you high evasion as a bonus. Sure, you might need to drop a weapon or a bit of armor to mount them, but shooting from the side or back makes up for the loss of the weapon, and shooting from cover with high evasion makes up for the lower armor.