If anyone out there is running the Legends please let me know the quality of you ride. I have the Legend FL-708 on my 2012 SG and it rides like a hard tail. I've contacted the Tech Support and here's what they told me:
You will obtain best performance and ride quality at 1/3 sag. The FL708 has about 2' of travel, so 1/3 will be short of 0.7" from max height. Inflate the shocks without sitting on the bike. Hold the button 10-15 seconds after the bike stop rising. When you sit on the bike with everything you are riding with, the bike should sag about 0.7". That is a good starting point for best performance.

You can ride it lower, but the spring rate will be lower and the suspension will be softer and you could risk bottoming out.

I've tried this for the last 700 miles and my back/kidneys are killing me. Any tips would be appreciated!

 

To quote from their website: "When installed and adjusted correctly, they will provide the best ride you can get from a motorcycle."

I haven't tried a Legend air system, but I have tried another brand that makes grand claims and found it wanting. The only thing we riders can do is alter air pressure, not damping, so if the suspension is not damped enough and we bottom out, when we increase air pressure, the spring rate becomes too great.

At least Legend are accessible and a sponsor, so hopefully they will support you and meet their claim.