E-Maculation

There appears to me a new virtualization option in town, and it's free!
https://itunes.apple.com/us/app/paralle ... 4709?mt=12

Parallels Desktop Lite has the ability to virtualize OS X on OS X -- or Linux on OS X -- for free. Windows is a paid upgrade.

The kicker here is that there's desktop integration for OS X guests, and 10.5 server x86, 10.6 server and later OS X versions all function on it. Plus, it can import any VirtualBox and VMWare guests that are fully shut down (no snapshots).

Thanks for the pointer, I´ll give it a whirl for sure.
Good point to have 10.5 or 10.6 in a VM on Sierra or higher.

I've successfully got clean installs of 10.7 through 10.12 on it now; 10.5 and 10.6 server are officially supported, but I haven't got my disk images to work properly yet. 10.6 client brings up a "tsk tsk" dialog when you try to import or install it. Supposedly there's a way around that.

Oh, and the disk space used is significantly smaller than VMWare and VirtualBox. It seems to be working with APFS to save some significant disk space for redundant info -- plus, it appears to use 7zip and rar somehow to compress things. Snapshotting is significantly easier than the other two options.