First, VirtualBox's performance has never been great, you'd want to use something like VMware. Second, why use a cross platform app inside VM? Using the VM onl

First, VirtualBox's performance has never been great, you'd want to use something like VMware. Second, why use a cross platform app inside VM? Using the VM only for command line interface through SSH will get rid of any lag. You can share the host OS file system inside the VM and use GUI app on the host OS against native file system and you won't have to worry about filling up VM disk. Connecting some $1k MacBook Air to an external monitor + keyboard would get you a decent desktop experience which you can even take it out. Not sure how that is any expensive.