Brian! i'm not sure on other styles, i've only used the Metallo 8m tubed kit/Parker with a spring loaded clip. what i found on 1 or 2, kits there was a difference in clip tension, so i went looking as to why this was happening and what i found was a loose screw, which is a simple fix,while it was in bits i thought id take a few photos to share here so you can see how a spring loaded clip works and how it can be tightened up. Now after using the Metallo for a while now, i find putting it in and out of a coat pocket is very smooth and easy i like it.
Time will tell if the clip comes loose again, if it does i will put a drop of Loctite on the screw.