I use a Matin curve neoprene strap.
It's better than the op-tech in that the edges are nicely stitched up, the bottom is rubber so it doesn't slip and it's more elastic so it seems to feel lighter.
Op-tech is better in that the padding area is wider so weight is more spread out, and the clip system is really very useful. Can detach the strap easily for storage outside of dry cabi, and my Matin strap does get in the way at times and I sometimes wish I can remove it more easily.