I got the MegaRail 80 and the MegaRail Z from the supplier. They look great! They’re both very beefy. They’ll be a huge improvement in rigidity over MakerSlide.
I have added them to the store, pretty much at the price I had anticipated a while back. The listing is very bare-bones at the moment, but I’ll add drawings and more information about the features and uses of the profiles as I find time over the next few days. In the meantime, here are some older posts: a description of both profiles, the two candidate MegaRail Z profiles (I chose the one at the top), and the post where I guess at prices.
Many people have asked whether I will design and sell a machine using MegaRail. Yes, I will! I have already started, in fact. (More on it soon.)