If you go to the Cotton Carrier website (www.cottoncarrier.com), they have a Facebook page link to actual user comments. They all are quite positive. There is also a good, in depth review at:
Sue Callan wrote:
I was at the expo too last week and actually put this holster thing on and tried it. Everytime I tried to lift the camera out of the holster it got stuck and the side of the belt came up too. I do own the dual strap system (Jessica was also at the show) and I absolutely LOVE it! Perfect for me as I am on the small size and it was so convenient having two cameras at my side, one with a prime lens and one with a zoom. But, of course, this is just my opinion. Maybe the guys will have better luck with the lift out of the holster, but it looks like it would be really easy to lose the camera........Show more →
+1
I was also at the show, and though I didn't try it on, I was resting on some chairs in front of their booth. The look of confusion and frustration on peoples faces seemed to tell it all. The main guy demoing it had a 1D w/ 70-200 on it. You could tell it was heavy, because he would keep switching it from his hips and his hands. I just don't like the idea of my hips supporting such heavy load all day. Their solution is to click a button and switch the side, but I wasn't impressed still. I also saw Jessica at the Adorama booth, and after she explained her dual strap, and I saw it up close. I remember some threads before talking about how her one had a better locking mechanism than the BR, so I bought one on the spot after talking to her. I've used it only once, and so far it's been pretty nice to use (although I wished there was a easier way to adjust it just right to your body). I'd say skip the holster, and look for the dual strap instead.
I use one all the time when shooting longer ceremonies. I keep my lesser used camera/lens on my hip until needed. It really helps keep the weight away from the neck and the shoulders. I have the cameraslinger too, but I think this makes me less tired throughout the day.
CTWalter wrote:
I'm going back to the Rapid Straps because I can't switch cameras fast enough. I was having a real hard time with the spider holster today. I'm a second photographer in Boston today (Sunday) using the R-Strap.
Does this mean you might be getting rid of your Spider system? Let me know.
I use the Spider Holster, use the strap to carry lens and flashguns. Also use homemade optek strap BR mod for second body. works a charm for when you want to be handsfree. To the poster saying about kneeling with 70-200, hook it the lens collar not the body and it balances fine.
by the way.......Pingol rules !! 
.. i'll report back when tested in the field