reds would be closest to browns in terms of actuation, although they are definitely a little more 'floaty' in comparison. Prepare for some period of adjustments when you go red for the first time; while the tactile bump in browns is small enough to be almost barely noticeable, it can be felt when you switch to reds. But they are close enough.
legends on the ergodox are mostly for aesthetics after the initial learning period; but if you like legends, you could probably get a normal labelled keyset from almost anywhere - and get blanks for the 1.5x and 2x modifiers from keycaps direct. Use DSA. Its a profile mismatch, but as one poster above have mentioned - it's almost impossible to get a full set of legended keycaps for the ergodox. The DSA retro set could cover most of it - but I believe the set is rather scarce at the moment - even more so for the sets that have every cap for the ergodox.
I don't really have a problem with the acrylic (in terms of durability) - and contrary to expectations - there isn't any flex to the acrylic when the keyboard is assembled (actually the middle 3 layers are thick enough by itself to be rather hardy, so no worries there). But I was careless while making some adjustments to mine during assembly, and I had a small section break off from that mistake. Not gonna happen if you're getting a fully assembled kit and aren't going to open it up again.
Qn: Is there going to be a full alu case option this time? I thought they were simply offering a top plate only for the anodised aluminium. As kurplop mentioned the first round aluminium was so bad that I'd be wary to get it without some sample pictures.
That said, the clear acrylic doesn't hold up well, to dirt, scratches, or even dust. Not an issue unless you're particular about the aesthetics of your keyboard. I didn't like it much, so I vinyled mine at first, then lasered another set instead later to replace the clear top layers.
For tenting, I'd always recommend fullhand.
I agree with kurplop though, massdrop had been extremely pleasant to deal with overall.