Well, johnkendall is an instructor & he says they all use them. Valhalla says he did fundies in one while his instructor used one. Sounds like everyone thinks it's DIR but me. I'm even more amazed to find out integrated weight pockets are DIR.
Just to be clear, we all HAVE them, we don't all USE them. I am planning on switching back to a standard harness at somepoint. I've been using the cinch to work out the small details needed while using one, but I've not found a real need for it with my diving.
Whatever happened to the KISS paradigm. Seems I know even less about DIR principles than I thought. Must be time for me to get out of the forum.
I wouldn't get all hung up on what is or isn't DIR. The cinch does add complexity to the harness, however the complexity is worth it in some circumstances. For example people with large shoulders often find it hard to get the harness the right size to both reach their valves and easily get into and out of their harness. The cinch can help here.
HTH
John