They have an even larger z axis then that. Its called the super z. Im not sure of the size of the jr v2 bjt I know its the same as the LC since it took its place. At Printrbot. Com they list under specification the size of the models. Theres all kinds of different firmware. The simple has atleast 2 different firmwares, jr is different as on of its axis is the opposite of other bots, the plus has its own and also Printrbot will soon be releasing even more firmware for the Printrbot plus v2.2 and v2.3, which makes your plus even wider. Also the plus has another one for the lcd/dual extruder setup and soon to have 1 for the triple extruder setup. Thats not even including all the non-official branches of firmware.
Check it out: Build logs, 3D printer news and all things Printrbot--http://reprapsquad.wordpress.com
PC Case Mods 3D printed:
RepRap Squad's The 1st Simple (XL)
* Custom built that towers over the LC
Printrbot Plus V2 W/
*Dual extruder PB Version (2-Ubis 1.75mm hotends)
*Heavily Modded and all axis extended