I finally got those DPV jeep kills and completed Scarred Veteran
lol
REX is a .44 only less range and stopping power and more fire rate
by stopping power, do you mean damage? in that case, no, because it's about the same
they both get two-shot kills from the waist-up (or is it chest-up?), and if you can't hit them twice in their chest, you should be using a G18 instead
range doesn't matter with pistols
and besides the fire rate, the REX reloads faster, by about half a second (which is a lot more important than it may sound), and has less recoil