Ok I climbed with it today. It's comfortable to stand on with my size 13's, it climbs nice, it doesn't slip and flop like my LWHC seat, it really grips the tree nice. I took of the straps off because I'm old and fat so I can't bend down to take them off while at height, you really don't need them anyway, I just put my feet under the cross member and climbed up and down that way, very easy, very stable. The cable has eyelets on both ends that the pins go thru and the arms have holes for adjustment. I didn't try it but I don't think adjusting while climbing will be that difficult.
I climbed a 12" dia. tree. I had to start 3' up because the tree was too big at the bottom. The left arm on mine had a hole that wasn't drilled in the correct spot so it was difficult to use that hole. I could use it but it was difficult. I don't like the wires on the pins but I guess they serve the purpose.
All in all I like it. Is it worth $300? I think so but the workmanship could be better, that hole should be right.