The debate on these strainer models is endless.
Acknowledging the success that many have had working with P83 and P85 models, I had several p85's that slipped. My best solution was to put a bit of nylon tubing on the threaded rod between the head of the tension knob and the throw off housing. I also used rubber bands, bits of velcro, and lots of tape, to keep the throws from disengaging.
Although not a unique problem, lots of folks haven't experienced the same.
So I switched to P86's which fit the same holes. The early ones had pitiful little set screws that snapped--probably a start on the negative side of their reputation. Since replacing the P86's have held up well for me.
Please try one and let us know which way your opinions land.