Muzzy,
Sorry I didn' t get back to you via Private Message.......I tried but my computer is doing some whacky stuff tonight.
You will be absolutely fine at 160lbs + your gear in the Cobra. That' s plenty of weight to get the stand to seat fully into the bark.
The upper section CAN shift if you bump it while standing, so be sure to anchor that section with the supplied packing strap.

If you are concerned about the platform shifting, don' t be. They stick like velcro, just give it a little forceful side to side wiggle when you reach hunting height to be sure all the teeth are engaged and its not going anywhere.
I have never in 6 seasons of using the Summit cable style climbers had one shift even the tiniest bit.
I' m not wild about heights but feel about as " at ease" as I' m ever going to feel in a treestand with a Summit.