I have a priefert, my dad has a filson.
My main knock on the filson is the bar that operates the squeeze. It is too heavy and will often fall down on its own, squeezing the chute when you don't want it to. Also, the bar is right at forehead height when in the squeezed position. I've hit my head on it more than once.
The back gate does not release easily. It is operated by a rope and if you don't pull and release just right it will not come down. Cows can back out of the chute while you're trying to get the gate latch to release. The latch for the right side door will release when you don't want it to. We put a chain on it after it opened at the wrong time and a cow walked out.
As far as the priefert, I prefer the scissor type headgate to the swinging type on the filson. No need to adjust for different sized necks on the priefert. Also, the scissor type backgate (this is on the bigger sized priefert) works very well. I am left handed so this may have a little bearing on my preference for the priefert, but I find it very easy to close the back gate and simultaneously catch a cow at the front. No ropes to get tangled with the priefert, another knock against the filson.
Finally, and this may not be the fault of the squeeze chute, but cattle seem to flow into the priefert much easier than the filson.
Having used both, I vote for the priefert.
