Maybe you've already ruled it out, but it might also be worth considering the Kinesis Freestyle line too. I've been using one for many years now after trying it at work and have been pretty happy with it. Since the layout isn't too different it's also easy to switch back and forth with regular keyboards. They have new bluetooth/mechanical versions now too.

I use it tented up in the middle at about 30 degrees with an accessory. The setup isn't very portable though.

Never heard of the Ergodox EZ. Looks great. Neat that you can replace entire switches with no soldering.

Most of my typing is done with my Kinesis keyboard on my lap. Doesn't look like the Ergodox can go on your lap, which is a dealbreaker for me.

Also, I mounted a trackpad|touchpad in the center of the Kinesis (with tape), and it's wonderful. Again, doesn't look like you can do that with the Ergodox.

I prefer the Ergodox because it takes less space than the Kinesis. Never used the EZ in particular. I spend most of my time with regular 80% keyboards or laptops.