Depends on how you design the return. Avoiding them is generally better because they are prone to failure and put extra back pressure on your pump. BUT, you must have a way to prevent excessive (I.e. sump overflow) back siphon. Best way is to just have the returns close to the tanks surface.
The fact that it is clear is good because you can check on the status of the valve but if you do use one know they aren’t foolproof. If used I would make it apart of my weekly maintenance and just check to make sure it is not stuck open
If you have an over the back return line, drill an anti-siphon hole just below the water line. It's a bit noisy when the return pump stops, but a surefire way to reduce the water flow from the display tank to the sump.