I just returned my ShapeShift 4.0 core pack today. I found the thumb release spongy and unreliable. It could have been a retention adjustment issue, but I wasn’t wild about it.
Ordered a Tucker DC-1 today to take its place.
I do have the AlienGear Belly Band and Closk IWB to try out for my K6S. Hopefully I’ll like that rig.