Thats the old Pivos unit based off Amlogic.
Basically almost all the Android boxes out there use two chipsets, Amlogic = stable video decoding but not very fast or Rockchip = faster but unstable video decoding (slowly getting better).
Pivos next unit which hopefully turns up in March I think they are saying is based off the next generation Amlogic line so it's stable but also faster with better CPU/GPU so it's closer in performance as if you were running XBMC on PC hardware.
There is no jailbreaking Android, it runs XBMC by just installing the application.
Other contenders;
Ouya = much faster hardware with Nvidia chip but runs custom Android OS fork, better option than going with one of the Rockhip based boxes, probably your best option right now.
AndroidTV devices = successor to GoogleTV official OS for set top box usage from Google, UI and apps are tailored towards TV usage and working with remotes whereas the boxes above use Android tablet OS which doesn't work out so well some of the time. A handful of AndroidTV devices where shown at CES, the
Hisense Pulse Pro being the standout one. Google are also rumored to be working on their own Nexus branded AndroidTV box.
Amlogic's next gen chips imply support for AndroidTV (formally GoogleTV v4), supposedly Google is being more liberal with who can use AndroidTV OS, hopefully Pivos next box is one of these.
In terms of quality level the AndroidTV devices should be in the same league as AppleTV or thereabouts but the unofficial Android boxes that are all over the place are definitely lower quality products.