I have the HSS system with the life line for my lock-on setups. It works great. There is a video on my site that shows me using the lifeline and the proseries vest ( www.ArcherRange.comclick reviews tabethen the channel 3 review).
It was very easy to use and when I threw the rangefinder out of the tree the first time I hit the limb over my head with my arm. It knocked me off balance and the lifeline kept me in the stand.
Don't know anything about the other vest you mentioned, but no complaints at all on the HSS.