I'm one of the BRCK team and I use the Karma when in the US traveling around. I initially bought it for testing and think it's a really well done device. What you should know about it is that it's only really good in US cities, as it uses WiMax backhaul. It's got decent battery as well. Their social mechanism for getting others to signup and get you free Mb really works (pro tip: Keep it on in the airport).

The BRCK was designed for a different use case. It's designed to allow more connections and to have failovers for poor power and internet connectivity. It also allows you to extend it with both hardware and software of your own making.