I have both a 3 and a 4. My 3 is dialed in pretty good that I trust it to just run. There is some quality of life things on the 4 that I like. The auto bed leveling is nice for swapping sheets without having to change z offset settings. For the price difference between the two I’d go with a 4.
That’s too bad. I am at the beginning of exactly that path. I have my Unraid running my containers and just started building VMs for myself, but I’ve had much better success in uptime.