my old sami was welded rear, and current one is spool. They roll fine in a straight line, but there is a lot of tension in the steering and twist when cornering. MY current one is could, so it does funky things, my old one was leaf spring and 33's so it just squawked a lot. I didn't wear tires, mostly cuz i didn't drive it onroad that often, but it was noticeable when i did. The bigger tires certainly take some of the bite out from that, but chew faster..
if you are going to be doing a lot of in town driving in your occasional trips, you will prob find the locker is better, if it is more rolling on the highway with a few turns, just spool it.