I, personally, haven't used the Chance Sheath. However, a couple months ago I grabbed a Basilisk Sheath. At the moment my partner and I have a love/hate relationship with it.

I really love the material. With a bit of lube, the soft pliable material feels great and can double as a masturbation sleeve if you would like. The ball-strap is nice and stretchy and I don't have a problem securing it.

The Basilisk allows the head of your penis, or shaft for those larger individuals, to receive stimulation while you're having intercourse. It's nice. However, my wife finds it extremely trying to accept the girth, and hasn't found much enjoyment from it. Additionally, even with proper warm-up, the sheath will sort of 'pop' into her vagina a bit when her lips are firmly at the base of my cock. This leads to a sort of weird feeling of pops when one is slowly thrusting in and out and also will cause the ball-strap to work a bit more to keep it secured in place.

The feeling, I have, when in my partner isn't bad, but it also feels a little like a phantom cock. I love that I'm stretching my partner out, but sorely miss the warm embrace of a vagina around my cock. At the moment, we don't use it all that much. That may change if I find a play partner that is really into being stretched out.