Definitely a worthwhile effort. I am using host only networking and running a handful of vms on a test domain. It's been extremely valuable

I ran into the same issues that Steve did with the latest virtual box. I wanted to export my rig for other members of the team but with virtualbox it just wasn't happening. When I switched to vmware workstation everything was much smoother.

I am using an external drive to hold my vms which has had problems when the drive is not removed safely.