Depends on the issue you are trying to address. TrailAir will handle an up and down motion, helpful when you feel like the tow vehicle has to much bounce. MorRyde handles more of a front back, push pull type surging. Once you decided what the problem is then you pick your pinbox
MorRyde also makes a pin box that works on the Flagstaff/Rockwood & the Pullrite Superglide.
Great advantage when you have a SB truck and need a 'slider'
BTW, it also gives a great ride...ask me how I know..lol