LXC is very nice. It's very VM-like and why I prefer it for almost everything I deploy instead of using Docker.
I know how to manage machines. I don't have the same confidence for Docker-images.
LXD seems to be a construction on top of LXC to make managing it easier "at scale", so if all you want is to manually be able to construct "container VMs" on demand, I think LXC is closer to what you actually want: It let's you manage the containers directly, near the iron, without anything getting in your way.
Don't get me wrong: LXD seems to have a genuine value-proposal, but for this use-case it seems to be a slight step of indirection, and my guess is that this will cause you more troubles than it's worth.
