I own at least 6 sets of Rapid Rails and they collect dust in the barn. That's because I can't get them totally silent in use. No matter what I've tried they invariably go "clink!" when putting my weight on them (200#) on a cold frosty morning. If I could get them 100% quiet (no exceptions) I would use them. A 'clinker' isn't going under any stand I hunt from...I just don't give on that issue. The Rapid Rails are by far the safest hang-on climbers I know of. They offer two very important features: multiple hand-holds and foot-capture. As long as you pay attention in climbing, they are nearly as safe as a typical ladder.
I've used a variety of screw-in steps for 35 years and I've not had one bad incident r/t the step failing. I've never had a foot slip off one, nor have I been injured in any way by them. I've left them in trees for years and they are fine. I only use them in places where they are considered acceptable, and where the quality of the trees (for timber) is not a consideration. My all-time favorite step is the Cranford Ezy-Climb single-fold, as the tapered screw is far and away better than others I've tried. I feel 100% safe on them, and I've literally taken thousands of steps up and down on them in my life.
One thing I've never cared much for with Rapid Rails and other aids is knowing that 100% of my body weight is being supported by a single nylon strap and metal spring-lock. I've never had one fail, but I've replaced some that were in bad shape. With treesteps I have 4 true points of attachment/contact when climbing, so if one fails the others are still in place.