I have the HF Quick Hitch.
Issue 1: Lower link width:
here's what I have found. "Most" of the Cat 1 implements meet, or are very very close for the 26" wide spread. BUT, some build their frame at the right dimension, and forget the Pins have shoulders on them...ooops, add another 1/2" to 3/4" inch overall. I bottle jacked mine to fit everything, then along can the KK tiller, had to bottle jack it another 1/4", no problem it works.
Issue 2: Top link height. My implements vary much more in height from C/L of lower Pins to C/L of Top Hole. It would be a pain to constantly unbolt the Upper hook for this.
Issue 3: Top Hole obstruction. The factory Hook should be able to rise up and capture the bolt or pin you have installed in the Top Hole of your implement, except, a lot of implements have flanges welded across the uprights , a few inches under the Top Pin Hole. ooops. That blocks the Hook.
Newer implements, I notice, seem to be using a different design to accomodate this issue. I used a fairly complicate assembly that still utilized the 1/2" height adjustment holes of the Quick Hitch. I will say I like the flat-stock approach that LimeCuda used, much easier and quite effective.
I am king of over-complication.
Issue 4: Just happened with the KK Tiller. The distance between the Lower Pins and Frame of the tiller would not accomodate those big hunks of steel that are the Lower hooks of the Quick Hitch. Solution: I had to cut 3/8" of an inch off of the back side of the hook. Not enough to ruin it's strength, but, look at the mods that had to be done so far?