Pat's is nice system in that the sidelink widths are adjustable but they snap onto the implement using spring-loaded hooks like the fixed width solutions. The benefit is more compatability but the downsides are you need to get off the tractor to install the toplink (luckily this is the easy part) and you may need a longer toplink to keep things in line (on my small 2520 this hasn't been an issue, but these are easy to swap out and it's an excuse to get a hydraulic toplink).
The downside of both systems is that the PTO shaft needs to be longer. Again, my shafts have been long enough (no snickering!) but I also have new implements that probably are designed for these things plus a smaller tractor.
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