Atreus is a split kb but on a single piece, so... not quite? For me the nice thing of a split keyboard is to have each half line up with my shoulders, feels really comfy to type like this (this way my arms rest on my chair's armrests most of the time).

I looked for a while for a nice split mechanical keyboard and I found all sort of crazy things, including the ones from [1]. In the end, I decided to try the kinesis gaming kb [2] and I really like it! (so much so I even got one for my brother :-) It has some cool macro recording keys and extra buttons to map and other features. Caveat: it is wired.

1: http://reddit.com/r/mechanicalkeyboards 2: https://gaming.kinesis-ergo.com/

The Atreus is by far my favorite keyboard, I have a Keyboardio that I never use because the Atreus is so great.

The key is to pull it off your desk and put it in your lap. You end up typing with your hands on your thighs, which feels quite natural and relaxed.