I don't program on the Arvo (or program at all, for that matter), but I can speak some to the keyboard as a gaming device.
Key action is fine, for what it is. I find them a bit heavy, but I started using the board after using a well-worn-in G15 for years. Also, I have a MX Brown keyboard that I use at work. I'm not certain exactly how NKRO the board is. I'm not terribly picky-- for instance my G15 never caused me issues. Unfortunately, I have had problems on occasion with certain key combos registering on this board. If I was a little more thoughtful and scientific, I could probably get the the root cause. As it is, I've learned to lift my hands completely off my board before hitting certain key combos in WOW.
The size is perfect for me, and once you get used to the game-mode on/off system, the 10-key and arrows are fine. The macro software is more than adequate and the thumb macro key location is divine. Unfortunate, I dislike the key action, shape and height of the thumb keys.
On a final note, the pictures that I found on the web of the Arvo weren't accurate. Specifically, the backspace key is narrow, rather than wide. This was problematic for me since I'm a terrible typist. However, it did push me to finally reprogram my Caplocks key to serve as backspace, which honestly is kind of awesome.