I'm not sure I have reduced the real estate grab as much as I can, for example I am running a Win 7 VM at 1280 x 800 resolution, however the Linux window it's running in takes 1372 x 942 pixels, in real terms that's over 25% overhead for a few menu's, scrollbars and bit's that I don't need onscreen all the time.
Well, you shouldn't have scrollbars at all unless the guest desktop is larger than the window. All that would be left are the menubar and titlebar and the window borders, and we don't really have control over those. If you want to shrink or remove those, you should try a different window manager.
You could try VMware Player instead (it's included as part of Workstation), although I don't think it'd offer much beyond Workstation after hiding the toolbar, tabs, and status bar.
It would be different because I can run multiple Win 7 VM guests in one Linux host workspace, this gives me the ability for example to have 3 guests running in one space or on one monitor I have I could run probably 10-12 VMs on screen all the time (the monitor runs at 3840 x 2400) . In full screen mode it would require user intervention to see each separate VM.
Okay, I see, you want the guest desktops to be much smaller than the host desktop. Maybe you could enable the built-in VNC server for your VMs and use a separate VNC client for each VM? (IIRC typical VNC clients don't have menubars, although they'd still have titlebars.) A tiling window manager (e.g. ion, ratpoison) might help.
Now before anyone jumps in and says but you could do that with Unity that requires too much configuration each time
Could you elaborate on what configuration you're referring to?
