Same here, I was buying some tractor stuff and the seller threw in an almost new Harbor Freight quick hitch, along with the "secret" HF adaptor for non-standard implements. Of 5 implements I tried it with, it would only fit one without serious hassles. I could have probably modified one or maybe two of the others to fit, but it would have taken some fairly extensive cutting and welding.
Pat's seems a bit better in this regard just because it doesn't try to do as much.
I dream of some self centering quick hitch that would allow simply backing up to the implement and instantly hitching all three points, and disconnect with a single pull of a lever. I gather they do exist, but would cost more that the tractor.