Yeah, for anything DOS based, I imagine dosbox is a better solution. It's how gog.com provides those older games when you buy them, and they have to support them.
gog.com provides many DOS-based games with ScummVM, when ScummVM supports them.
Sorry, I actually knew that and forgot. I didn't actually mean to imply dosbox was better than ScummVM for DOS games, just that it's probably better than a full VM when it works. ScummVM is probably as good or even better than dosbox for the things it supports well, so would probably be better than a VM too.
I couldn't get DOSBox working on 64 bit with Ultima 4, sadly.
Today I learned about xu4, but it looks like that code became part of ScummVM, so it's the same now.
I could never get DOSBox working on 64 with with ultima 4.