I ordered this anti-slip strap for the purposes of replacing the original strap that came with the first version of the Gruvgear Gigblade. That strap was not very good either comfort wise or for preventing the Gigblade from slipping/sliding off the shoulder if carried 'shoulder style'. In use, the anti-slip strap that of note comes as standard on the Gigblade 2, is an improvement on the earlier version strap. That said, if walking for the long haul, this newer version strap will still start to slip off the shoulder, but not as quickly or as easily as the original strap did. Additionally, comfort is improved as there is a thicker more uniform layer of padding as well as a rubberised texture to the material on the underside off the strap.
As for pros and cons:
Pros: a fairly inexpensive price for a well made strap, in addition to an improvement in both the strap's comfort and anti-slip properties.
Cons: not as non-slippy as one might assume, and you will still have to lift the strap over your head and carry the case behind you with the strap across your chest if walking a long distance.
Would I but the strap again? Yes I would. It is well made, is fairly comfortable and does what it says it is supposed to do to some degree.
All in all, if you have a Gigblade one and are asking yourself if this newer version worth buying, in my view it is for the reasons highlighted.