Bought them for gluing up large wood panels and they work well for that purpose. Parallel bar clamps are typically a bit on the pricey side for clamps, so I was hesitant to buy some for a while. These seem a bit cheaper than some of the more well known brands like Bessey and Jorgensen and while I haven't used any other brands, these ones seem to work quite well. The jaw moves relatively easily once you loosen off the thread and lift the handle. I only bought four, but I've set them up on either end and spaced the other two evenly in the middle, then supplemented this with additional lever or F-style clamps in between for longer glue-ups and seem to have gotten pretty good results. The bar is a sturdy steel bar. There are plastic tabs on either end of the bar which helps it sit level on the bench while setting up. The jaws are large and strong and covered in some kind of hard, rubberized polymer that grip the workpieces firmly. They seem capable of a tremendous amount of clamping force - far more than you're likely to need for panel glue-ups. The only negative I can think of is that they only seem to come in the 50\" size. That's great if you're gluing up 48\" wide table tops or similar, but for narrower counter-top and desk panels, a shorter bar would be nice, but I mean you know that going in, so it's a bit harsh to take points off for that.
Sami 
