Any way of hiding this beast under a table?

The EP600 is available in a horizontal set-up, I'd imagine the 800 could also be had the same way...I'd give Axiom a call.

Yup, my EP800s that I have right now, which were supposed to be vertically-oriented, are horizontals. I'm still using one upright, however. The other one I actually am using on its side, and it's sitting under a table. I'm not using the feet on either right now.

Henry, Order it in Horizontal configuration.

Yes you can do this, I actually have a horizontal EP600, that I often place in a vertical orientation. Keep in mind that the position under your table might NOT be the ideal position in your room for best results.

I find that placing it under a glass table with lots of Fine China on top adds to the experience.

What is the actual difference between - vs | ?
My guess would be just the orientation of the amp controls and the location of the feet.
Is there anything actually acoustically specific between the two?

Nope, unless you take room boundary interactions -- which are specific to each room, of course -- into account.