I sorta piece-meal'd mine so I'm not sure if this counts, but I couldn't imagine the full-hand would be comfortable. Even "soft" acrylic is pretty hard to be resting your hands on; better to get a classic, and something spongy (or hey a Noko rest if you're flush with spending cash) to put the palms of your hands on.
Of course, type with the keyboard in my lap, and that has extra considerations where you've got two separate small keyboards ... I'm using a keyswitch plate from a donor-ALPS-board but a plank of 2x4 would work too ...
Honestly, a top-plate of *just* aluminum? If I had the top plate be different, it'd be made of nothing (I still consider this route)
I'll be running another set of aluminum or stainless cases, if you want to have an all-metal case. I'm really glad I pulled the strings to make my ergodox weigh five pounds of I-could-kill-a-man metal so it's something you may want to give consideration to.
answered in approximately the order you asked them; possibly without any preamble between answers. Good luck, and welcome to the Ergodoxen crowd (err, once your kit gets here...)