So it appears the OP has made a choice but, in the spirit of these forums, we'll keep on commenting because :-) we just can't help ourselves from being helpful.
So here's my two cents:
Please see my original review of the Peak Design Slide here:
Peak Design Slide reviews - Pentax Camera Accessory Review Database
And the ensuing discussion with lots of helpful advice here:
https://www.pentaxforums.com/forums/22-pentax-camera-field-accessories/308067...de-clutch.html
Now that some time and experience has accumulated, I would like to add these thoughts: I use the Peak Design slide, slide lite, and leash for different purposes, and have found them to behave flawlessly for each. Here's how and why:
1 - The Peak Design design is really strong. For anyone worried about this thing giving way because it's attached via your tripod screw, that's just balderdash. Or, major user error. In which case, you shouldn't be carrying around expensive equipment until you can be trusted with it. No, seriously, this system is STRONG. And, by the way, you can use a quarter to tighten/loosen it. A major plus in my book.
2 - I use the heavier Sling to haul my K3II with the Sigma 150-500. I attach the sling to the lens and feel very comfortable having that weight hanging over my shoulders. So great for quick lifting to get that fast shot, then back down it goes. You so want that big lens pointing down and stabilizing on your hip.
3 - I use the Sling lite for carrying the K3 with anything lighter than the Sigma. Often, the 18-135. Or 300. Love the way it carries and you can pick it up and let it down at a moment's notice.
4 - speaking of carrying, please see the photo below. Many folks are carrying their cams/lenses with a singular attachment point. I can tell you after many miles of trekking that allowing the gear to settle on your hip with two different attachment points is fantastic. It doesn't bounce, it doesn't...do anything. I just sits there flat on your hip waiting to be deployed. There are always individual preferences and I respect those, but do think twice about the advantages of dual-point attachment before you commit. I love it.
5 - I use the leash on everything lighter than my K3II. Like, my little Sony M3. The leash is perfect for lightweight or mirrorless cams.
I enjoy the heck out of this set of leashes/slings. I've decided my favorite is the Slide Lite. I'm ordering another one right now.