I use the Scotts damper and run a BRP Rubber submount. With 65mm riser built into its design. Which works out much better for me when standing. The BRP has rubber isolaters built into the bar mounts. The set up comes with different density bar mount bushings and reduces vibration on my FE 501 tremendously. By far the best set up and no sharp edges on anything like some of the others have. It has more adjustment range than the others also in my opinion. with regard to turning motion. Mine came with the hardware to space the instrument cluster up higher as well. A new reduced head top nut for the stem was provided free and the larger knob for the right hand fine adjuster was also included free of charge. The left knob is for hard sharp high speed hits the right knob is for fine adjustment like when you drop into a high speed sand wash. to keep the bike going straight an reduce the side to side motion and reduce arm pump.
I believe that only a street bike should have dampening action/rebound back towards center as the bike is leaned much more into turns. not turned while sliding like a dirt bike. Street bikes would have this rebound damping action for like when pulling the front end at speed and setting the wheel down at speed with the front end turned slightly. Without it, it would go into a speed wobble from the steep steering head angle as the forks compress.
IMHO a dirt bike shouldn't have this return to center rebound dampening action at all because it makes it easier to make corrections steering the bike in turns while sliding the rear wheel of the bike. The bike wants to go straight so it returns back to center easier.
You can see an adjustment screw there on the side with a flat head and a dot. That controls how far of a sweep the dampening affect is. It has 4 sweep positions of dampening from the center to 4 positions right and left. If your bike has a total turning sweep from right to left of say 90 degrees. The adjuster allows or applies dampening with this adjustment of 34degrees to 44degrees to 54degrees to the last position of the full sweep of 90 degrees. This last 90 degree position wouldn't be used on a dirt application. I like the Scotts much better than my GPR it and I got it through "Jeff Slavens Racing". No fuss and no attitudes, great service. I love it.
I have a GPR on my other bike A G450X with a Submount and have swapped the damper itself between front ends on that bike with just the Submount change to fit the KTM different front end and trees I upgraded that bike to run.
Never tried the "Fastway Dampers or mounts. I here they are very good too.
I can't give any comment on the actual operation of the Motosportz damper either (which I had initially inquired about purchasing at first). I tried to buy one myself through every avenue possible, posted a request to purchase on a thread, sent emails, Business phone calls, PMs on this forum and was told the mailboxes were full. So when making phone calls I couldn't even leave a message at the business contact number. I never got any response back from any of my inquiries. So finally I was told a few weeks later after I had already fitted the Scotts/BRP set up. Directly that the owner of the company didn't respond back because he personally would rather not do business with me, openly right on this forum.
And we are asked to support these businesses. Which I do and don't have any problems with buying product from "ZipTy and 7602 racing". 2 of the major sponsors.
So there you go. Go with the BRP/Scotts. You won't have any problems getting parts if you need them and it is a well thought out product and it performs and works great.
Everyone who rides my bikes in the sand washes here can't get over how they rail through the sand and rocks without any hint of the front end getting jerked or pulled around by the pounding.
Now it's just up to you to decide who you want to do business with.
You let people ride your bike???