I can attest to how much easier the removable window is for working in the back.  I was making templates for insulation/upholstery in the back and can't imagine how I would have done it without Dave's removable window.  It saved my bacon!

It makes me think of putting one in my Super ES when I get to that stage since if I ever ground loop and have to get out while inverted, that's the best way.  Externally, it looks identical.

Dan Newland