It largely depends on the model. I had the SLR Zoom version for some time - it worked within its limits. However, one of the plastic cups broke (its quite a common problem), and from then on, not only wouldn't it grip onto anything, but it couldn't even hold its own weight up when using it as a mini tripod. I now have the focus version (with metal cups in the legs), and it is good for what it is. However, if wrapping around something to mount a camera for any long duration (more than a few minutes), I'd only consider using it in combination with a good buckle strap tightly wrapped around the legs.I tried one in store and could not get it to hold onto anything.....Tied with the "tripod" that has flexible legs and can supposedly wrap around a fence post or branch.I really hope I am not the only one who fell for that, this thing can barely carry its own weight, but it really reminded me of the "buy cheap, pay double" saying
With the model I know they're smart enough to put it into a tight casing so you have to buy it before realizing that it's no good ... and in addition to that I ordered mine online, not a large loss of $$$ mind you but that's probably just what keeps them going.
Love mine. Holds my 5diii with grip and 16-35/24-105/100 IS with no problems. Much easier to hike with than a full size tripod.
My preferred long term mount of choice is the Manfrotto Magic Arm with a Super Clamp.