I 've never heard of these prior to this post. Due to the attractive price. I did a little research. I found a lot of references on various forums, but mostly there were only questions; no answers. I found a few bad mouthing them, but they didn't offer any real information. None really claimed to own, just that they heard they were no good.
I contacted a vendor selling these and asked several questions including available spring rates and valving options. Their response was "Per Matris the fork cartridge kit is set up for a medium sized person about 165-185lbs; we do not have the option of switching this out."
Based on this information I have eliminated these as an option. They sound like a nice product and the price is right, but with lack of knowledge and parts they could be an expensive paperweight.