Got almost an identical set from Hong Kong on eBay for 1/4 of the Adorama price. Very solid build, smooth travel, etc. No quick release here. (Didn't see it on the picture of the Adorama set either). I do need to manually screw the camera or lens mount onto this rail. But once tightened, it's solid like a rock. I moved by Canon 40D+grip+Tamon 180/f3.5 on the rail all the way to the end in both directions, nothing loose, shake, or vibrate! Check out on eBay if you like. Again, I have no relationship to any of the sellers on eBay. I think the Adorama set is just my cheap set with a brand name label.

I just received my focusing rail fro Adorama. Very well built, smooth travel on either axis and made of heavy duty materials. Best of all, it says "JAPAN" on the outside - What do you know! A product not made in China! All in all, performs well and is a real tool that will last for many many years.

Worth every penny for macro work. I've tested mine and it does a wonderful job.

This product is very good for macro photography. Moves left and right, foward and back so you do not need to move your tripod to get in position again to reframe or focus the subject. Smooth and very small fraction of an inch foward and back movements allow for macro subject to become in focus without having to go back to lens focus ring after you have previously set the len's depth of field. Great for when an insect moves in any direction as you do not need to move the tripod and miss the shot.
One thing Adorama missed. A quick release instead of the screw to attach the rail to the camera so if you need to walk to the next shot you do not find yourself walking with your camera dangling around your neck with the bulky 1 1/2lbs. rail. The rail should have a quick release and be attached to a ball head with a quick release that is attached to a macro photography type tripod. The rail quick release will allow you to walk with it attached to the tripod and have no need to break it down or keep it attached to your camera.
Over-all a very good product.