I have 3 rear remotes on my L: 2 center return (double acting) and one float detent. I have a specific use for the float and I knew it when I specified it.
Some of the areas I brush hog are rough enough the range of motion allowed by the flex built into the toplink hookup on my brush hog is insufficient which resulted in binding unless I totally removed the turnbuckle type manual toplink. So my process for mowing the sewer line with manual toplink: 1) shorten toplink to shortest position to prevent binding when crossing creek cuts to get to sewer line; 2) extend toplink and remove to mow first of three sections; 3) reinstall toplink to pick up brush hog to cross rip rap lined ditch to second section; 4) remove toplink to mow second section; 5) reinstall toplink to cross rip rap lined ditch to access third section; 6) remove toplink to mow last section; 7) reinstall toplink, shorten to shortest position for those creek cuts on the way home; 8) wind the toplink back out one last time when back to the shed if removing from the tractor. If you’re still reading, as painful as I’m sure it was reading that, it was worse actually doing it two to four times per year.
With the non-check valved toplink on a float valve, current process for same job: 1) When approaching creek cut shorten toplink with a small flick of my right wrist (no need to stop the tractor); 2) Put the toplink into float to mow first section (another wrist flick which doesn’t require stopping); 3) Take it out of float to cross the rip rap ditches; 4) … I’m sure you get the idea.
Using a toplink without check valves (as others have mentioned, you can’t float a check valved cylinder) I can float the toplink rather than remove it and that’s worth something to me. Yes, I’ve floated the side link with the box blade a couple of times by swapping the lines around. Other than my one job described above the float isn’t some grand game changer of a feature but I also haven’t seen any real downsides to it aside from cost.