This thread is a great idea. I think lion calling is going to become a lot more popular with how many cougars are around. My cougar this year called me in but im hooked! It was an adrenalin flood I may never have again but I think calling them in to me may come close. I too would loose the decoy. And put your call in or on some brush. Curiosity killed the cat. If he can't see what's making the sound and can not check it out from a distance than it must get closer. I'd put the call in a patch of brush so that you can see down in to it and around it but anything approaching can not see in to the brush from the outside edges. Only decoy I was planning on trying would be a doe decoy on its side or set up in the brush. Im no expert. A cat is a cat is a cat but it's also a very cautious predator
I think you are right about the decoy, too open too visible. If a cat got eyes on that it might just lay up and watch it and I wouldn't know it was there.
by the same token though a decoy might bring one all the way in.....
I think I'll hide the decoy better so they won't see it until they're reasonably close, if I switch to archery and tree stand hunting the thicker stuff a decoy would be great.