The beauty of the Muddy Outdoors safety harness system is that you’ve got the option to use one or the other as both come in the kit. I’ve been using this now on at least a dozen or so hunts, and I cannot believe how much better this system is compared to the standard harness systems that come with a treestand!!! It’s a piece of gear I actually look forward to using because of how slick it is, and how much better it works than what I was used to using.
As for securing yourself to the tree, for me it’s easier to have straps on every tree I hunt, then just clip on to the strap with the provided caribeaner on the back of my harness system. As for the lineman’s belt, I can see how that would be useful for several of my stands. If you have to contort to one side or the other, partially or mostly turn, or stand-up/squat-down to get the right shooting angle, I think the lineman’s belt would be more forgiving.
That said, the Muddy Outdoors belt and the strap on the back is longer than any of the other safety systems I’ve used, almost always giving me more than enough room to maneuver.
Joel