That decision had already been made@M635_Guy if you decide to go with traditional fixed extensions, check out the offerings from Mac Tools. Great quality and nice knurling on the female drive end and shaft.

I was kinda second-guessing myself and was considering swapping them out for the Wobble Fix or maybe ordering a couple of individual Wobble Fix extensions (which I still might do, but going to wait).
This whole thing was inspired by me doing some suspension work recently. My garage is tight, and on one side I'm kinda pinned against a wall. My extensions kept rolling under the damn car, which was really ******* me off. I really like the Koken design for its resistance to rolling and the knurling.