This is a very nice write up about LXD and Multipass by Jon Seager. He’s not exactly neutral as a Canonical employee, but I agree with just about everything he says about LXD. It’s a really nice system for running containers and virtual machines.
I haven’t used it much of late, but I found it to be a powerful and flexible. I was concerned that it would lose mometum when one of the principal developers left Canonical and forked the project, but LXD seems to be progressing quite well as does Incus. This is a comparison between the two.