My search-fu is letting me down right now. I have looked at the design of both Heighway machines and the side rails seem really wide/think over the glass. I've also read about some "system" that allows you to swap between games. Is that the reason the boarder around the glass is so thick? If so, does anyone have a link with more info about it?
The aliens design looks very promising from what I've seen so far. Looking forward to playing it!