I wonder sometimes if it is in how they are setup. I have more experience with various lockers for off roading / rock crawling. I have had some that you had barely any idea they were there and others as stated above that would jump half a lane when shifting or letting on/off the gas quickly. This was on stuff I bought used- the drop in lockers are all pretty similar in design and none of them are limited slip clutch type units.

I hear the same thing with detroits- some people report a good amount of noise and some quirkiness when turning and others swear it behaves nearly like an open rear.