I have a float detent valve that I use on either the toplink or sidelink depending on what I’m doing. Neither cylinder has check valves. There’s good and bad to that.
Good: I can float the toplink to allow gauge wheeled three point implements to follow the contour of very uneven terrain without binding or having to remove the toplink or replace with a chain. Swapping hoses to put the sidelink on the float valve, I can float the tilt to follow the contour of the ground, which is quite handy for some grading operations such as pulling gravel in from the edges of a gravel road or cleaning ditches.
Bad: Valves leak (at least the valves for our little tractors do) so without check valves, the cylinders won’t hold position forever. Whether the leak down rate is problematic depends on how leaky your specific valve is (I can’t predict that but others may be able to), what you’re doing, and your expectations.
Workarounds/practicalities of using top/tilt without check valves:
1) Sidelink: I always run the hydraulic sidelink. I moved the manually adjustable sidelink to the left side and adjusted it such that the hitch is level with the hydraulic link is full up. If I’m running something such as a bush hog where I want it to stay level, I bump it up every once in a while whether it needs it or not. The leakage on mine isn’t bad IMO, so it isn’t annoying to me but YMMV. If it really bothered me, I could swap back to the manual links when I really want to “set and forget” for some lengthy time, but I never do it.
2) Toplink: My toplink is pretty short. It goes just a bit past level at full extension for most of my implements. For something such as my chipper where it really doesn’t much matter, I don’t care if it leaks to full extension and stays there forever. My boxblade and back blade, the toplink attachment point on the implement is forward of the lower link attachment points, so the hydraulic toplink will go past level; a necessary function for those implements. For the blades, I’m messing with the toplink routinely throughout the work, so leak down is not an issue at all. I have one implement, my skidding winch, where my hydraulic toplink is too short to achieve proper angle, but it’s a “set and forget” implement where no adjustment to the hitch is needed once it’s set up. For that one implement, I remove the hydraulic toplink and replace with the manual toplink. It’s one pin and two quick connect hoses to swap toplinks; easiest implement swap I have.
I’m aware most seem to prefer check valves. For my use, particularly grading work, I would not trade the ability to float for eliminating leak down. IMO, you have to consider what your uses will be and determine what setup best matches your needs.
I would never be without hydraulic top and side links and a QH. The side link is useful, but the top link is essential, and for so many reasons.