I was just about to do a quick release post, and then Ducky did his Mega Clamp posts, and I waited. I have a varied mix, and also agree the really light ones are, well, really light. There are some winners in this category though, but like Ryan mentions, increased cost is definitely in play.
Good post, it shows the noobs looking to start collecting clamps while these look like a deal due to lower price, they sure aren't heavyweights. Taking those funds, and moving up the scale is a good move though. Plus at 40 pounds of pressure, they are not real good when it comes to actually clamping. Most TB adhesives call for around 150 pounds of pressure for a good bond. They could be helpful though if you were trying to hold 2 pieces together to screw in a pocket screw or similar. So they are what I call, kinda clamps.