I've had one for years. It's similar to the Ameristep Doghouse in size and shape, but I can't remember who makes mine right now, and it's too cold to go out and look at it.
Mine doesn't have a scent liner in it, but it does have a black liner and prevents animales from seeing movement or your outline. I've heard several people say that you should put it up weeks before you plan to hunt, but I never do.
I've had deer and turkeys walk within 5 yds of it less than an hour after putting it up. If you keep relatively still and the wind is right, the animals don't pay any attention to it at all.
This past spring I took my 9yr old and my 6yr old out on the same morning. We set up the blind, put a plastic bench in it, and we wrapped up in a big sleeping bag because the morning temps were in the upper 20's. My buddy was calling for us, he was sitting about 10yds behind us. We had 11 hen turkeys walk right past us, 8 or 10 yds out, and spend over an hour pecking and scratching right in front of us. Even though I was whispering in the boys' ears about the birds and stuff, they never even knew we were there. About 2 hours later, 7 does walked within 5 yds or closer and spent about 30 minutes browsing right there. One was so close, I could have killed her with a spear.
I'd call them pretty effective, IMO.