My reason for shelf isn't aesthetics but all the points that you mentioned. In my (inexperienced) opinion, the epson is much more suited for shelf placement than flipped. It was much easier to set it up and adjust zoom, focus & lens shift when it was placed on the table than it is on the mount right now which is a nightmare in comparison. Maybe its the mount that I have? Which one are you using? Does it not shift position slightly when you try to adjust zoom/focus? Mine shifts a few mm everytime I touch it and that results in the image shifting a few cms vertically or horizontally (sometimes both)
As far as lens performance is concerned, wont it be more or less the same in both flipped and normal positions as long as the placement is the same? Instead of using say 20% vertical lens shift upwards, I'd now be using the same 20% lens shift downwards. So what difference it'll make if I place it normally instead of flipped?
Also, as far as IR is concerned, that point is mute as well as the new epson's use bluetooth for 3d glasses.
Not arguing here. Just want to make sure I'm not making a mistake by placing the PJ on the shelf instead of getting it mounted in my new room