Update on my opinion of the QuickBite couple.
I have now hitched/unhitched a dozen or more times, pulled the trailer many hundreds of miles, and it's been more than half a year.
I like it. It reminds me of coupling with a 5th wheel, though it's necessary to get the trailer altitude pretty close to lined up.
Coupling is as easy and quick as the videos suggest, even though I don't bother with the fiberglass rods. I can tell if it latch by sound and feel. The fact I don't have to jack the trailer up, back under with the ball, and lower it back down is sweet.
Uncoupling is just as easy. Since the coupler "retainer" is in the front, the ball cannot have any aft-ward load on it - which is just the opposite of the stamped sheetmetal coupler I replaced. This too is like a 5th wheel, and I consider it much safer as it means I have to back the trailer against the chocks so there is no possibility of the trailer rolling away from me when I unlatch it.
I like it better than the Bulldog hammerblow I also own, though if I were using an Andersen weight distributing hitch I would only use a Bulldog. When the QuickBite is closed, the back 90 degree (horizontal) is open as that allows it to hinge open.
There are limitations.
With my 15,000 lb (6,800 kg) Curt ball, there is 15 degrees movement fore-aft and athwart. 15 degrees is plenty - until the tilt of a weigh distibuting hitch head is figured. It could be tilted more than 5 degrees. This leaves less than 10 degrees tilt between the tow vehicle and the trailer. This has not been a problem for me - but I have seen setups where I expect it could.
There is 3/4 inch (19 mm) of "extra" in front of the coupler for the guide rods to attach. This is ever more than the Bulldog has sticking out in front. On my hitch, I put a washer under the ball to raise it 3/16 inch (5 mm) to insure the coupler would not hit the ball mount. I suspect some mounts and hitches could have problems. On my QuickBite model 7700 for a 2-5/16 inch ball, the front of the closed jaws is 1.625 inches from the forward most point on the ball itself.
It is not exactly the same size/shape as the old coupler, so I had to drill holes in the QuickBite to match the mount bolts in my trailer frame and the original tongue jack won't fit without other modifications.
I like it enough I'm contemplating replacing the Bulldog on another trailer with a QuickBite - but that would be mostly a lateral step where on this trailer the QuickBite was clearly a step up.