You can buy metal ones that hold up better and support more load for similar prices. Are these really any good? I have broke every plastic clamp I have ever owned.
How much faster is working with this style vs. metal twist style? I don't find the metal ones to be that time consuming at all.
It's not a question of speed. Those DeWalts, as well as their imitatee, the Quick-Grips from Irwin and other similar clamps, are about ONE HAND. The clamp allows you to hold whatever in place with one hand, and use the other hand to tighten the clamp. That can be anywhere from tricky, to impossible, with a standard F-clamp. They aren't for honking down. If you need to honk down, you can use a Quick-Grip to hold whatever it is in place and then put a screw clamp (F-style, C-Clamp, etc) on and really crank.
That said, I bought a set of the DeWalts when they first came out, not impressed. The best one handed clamp would be a cross between the Quick-Grips and the Jorgensen. The Jorgies have a much more comfortable grip, while the Quick-Grips I have (they are legion) have been flawless in their functioning. From what I've heard, the HF knockoffs do a bang up job of living down to the low expectations that often accompany HF.
