They can be hit or miss in my experience. I have one, made by Titan. It fits my landscape rake made by King Kutter, "kind of" fits my 6' mower made by Titan, doesn't fit my box blade made by Titan, doesn't fit my trailer hitch made by Titan. The Titan brand implements that don't fit, are all labelled "quick hitch compatible" in their description written by Titan. When we (my dealer) contacted Titan directly about these not fitting, their official response was "sound of crickets".
The ones that "fit", I have installed the adapter bushings on the lower pins for use on the quick hitch. So if I wanted to use them without the quick hitch, the bushings would have to come off first (kind of a pain to put on, so probably a pain to take off). Also my neighbor wanted to borrow my rake once, but with the bushings on the lower pins, he wouldn't have been able to use it on his tractor since he doesn't have a quick hitch. I was using my mower on mine at the time (also using quick hitch), so I couldn't just easily loan him the rake + hitch. Ended up taking mower off and just using rake on my tractor at his place, then coming back over swapping back to mower and continuing my mowing at my place.
I also went with the removable pin setup that Bolt On Hooks sells for adjusting the top hook position on the quick hitch. Even though I only have 2 attachments that can actually USE the quick hitch, they each need a different top hook height position to hook up. So I have to change the hook height when I swap one to the other. Most of the time, the mower sits on the 3pt in summer, and the box blade in winter anyway.
Not sure I would do it again (get quick hitch) myself. Depends on your situation. My lower link arms on my 3 pt do extend, and both sides are adjustable, so hitching up straight to the 3pt isn't as difficult as some would be with just straight arms. And even when I use the quick hitch, if I'm changing from one attachment to the other, I'm getting off the tractor anyway to 1) change the top hook position, and 2) for the rake, it's so light weight the tractor lifts it off the ground before the top pin drops all the way into the top hook anyway, and I have to get off and lift up the back end of the rake to get it to drop into the bottom of the hook all the way.
TL--DR
If you get ALL your attachments from the same brand as the quick hitch, and they are NOT TITAN, and you test them all against your new quick BEFORE you buy them, and they all work together, then you may have something worthwhile. If you're buying various attachments from different sources OR TITAN, they will probably be more of a hassle then they're worth.
I will probably do away with mine eventually. Maybe another season or two of grumbling about it first.
