@Hellsbellsidaho I will be the dissenting voice - it’s up to the individual to decide what is a waste and what’s worth it.
I cast an epoxy granite table for my machine. It absolutely sings cutting 1040 with the default High Carbon Steel roughing feeds and speeds with fusion’s Adaptive toolpath. I don’t have a stock MR-1 to compare it to, but I’ve heard some people have had to derate their machines and that they experience high levels of enclosure vibration. My machine shocked me with how quiet it is, and I feel like I’m only at maybe 3/4 of the max performance envelope.
I think there are some inherent risks with concrete and cracking due to freeze thaw, if your shop isn’t temperature controlled. That was a big reason for me. Time will tell if people see this issue with their concrete builds I suppose. There is certainly a lot of variety as far as concrete prep in the field. Some people are pouring concrete that does not inspire a ton of confidence… but even crumbly garbage will give you some mass damping.
Epoxy granite cost me about about $800 over portland cement concrete in epoxy alone, and was perhaps somewhat more challenging to mix, although I managed it on my own.