I vote for
lenscoat body pouch
I tried both optech and lenscoat at Adorama, and looked briefly at Zing. The optech had a snap closure, which wasn't good for me. Required too much manual dexterity, and limited the "fudge factor". The Lenscoat is velcro closure. Both are similar thickness neoprene.
I think the Zing was thicker neoprene, but I don't think they had a body only cover. (I was shopping body only covers for a DA40 setup)
Here are some rough pics:
K100d+BlackRapid+Lenscoat