Well it sounds like your expectations might be a bit high for a home based cnc mill like mine. Of course there are things I want to change but really it won’t be drastic it will just be better. New parts are in the works. But we are using conduit and plastic parts so there is a limit to ultimate rigidity with this recipe. My goal is a machine that is as inexpensive as possible that you don’t need a cnc to build it and the parts are easily sourced world wide. I have no problem with cutting “slow”. Slow to me is much better than not at all, and slow vs. not at all is hella fast!
As for the machines you linked you are making assumptions as to which one is stronger by its looks. That is not fair at all, you really need to use a machine before you make assumptions. Happens with my machine all the time, plenty of people say it can’t cut anything but foam, I am pretty happy with the aluminum parts I make. All geometries have their weaknesses, I personally do not like that one. Have a look through the build guides for those things and look at the part count and variety. You will always save money by buying those kits, not to mention you have to already have a cnc mill to make the parts.
The “triad” needs to get tested out soon. I think using 3 is still the best option, EMT is steel so adding hardened steel rods isn’t very beneficial. We are still using a high point load. I have rotated the bearing on some test parts and it helps but I don’t thing enough to justify the extra parts. Conduit is cheap. When you get grooves that are too deep for your liking you can just rotate it a bit. After a full year of using mine 24/7 I haven’t needed to replace them yet.
Keep an eye out for new parts. Hopefully now that the printer is just about done I can start on the rest of the updated parts.