My new 8350 is mounted 21.25" above the top of the screen. I am pretty much using all the available lens shift the projector provides. The Epson 8350 does not have keystone correction but you don't need it as long as your projector is level and parallel to the screen.
Why is my projector located so high above the screen?
1) Because I can, the lens shift allows much placement flexibility.
2) The projector is as far away from my ears as possible, even though the 8350 is the quietest projector in its price range, I don't like to hear projector noise.
3) I didn't feel like installing ceiling mounting plate and down tube extension, just more cost and if I don't need it I didn't want to bother.
4) The projector mount, even though it's only 5" from the ceiling, gave me the space from the ceiling that I needed, even reused some of the existing mounting holes from my last projector mount.