And here is one more picture for the historicans.
The evolution of all prototype generations of the PCBs in one picture...
V1 ............ V4
V2 ............ V4.5
V2.5 ......... V5
V3 ............ V5.1
................. V5.1.3
V1 was a first prototype to test the magnetic Nubs and get a general idea how it could look like
V2 got new shoulder buttons, s second USB port and the idea for a 3G/4G version and moved the potentiometer and connectors around
V2.5 got the idea for a replaceable CPU board (hence space for some - too small - B2B connectors)
V3 was the first one which worked with an adapter to the OMAP5432EVM and aligned connectors etc. with the plastics case design
V4 was the first one to work with a real CPU board
V4.5 got different SD slots and the eSATA connector was replaced by an USB3 socket
V5 changed the WLAN/Bluetooth module (the originally chosen one is no longer available) and became the first handful of prototypes shown e.g. last year at Gamescom
V5.1 tested a new µUSB3 connector and again a different SD slot
V5.1.3 is the latest production run with redesigned CPU boards (you can see a cut-out for the WLAN module)
V5.2 (no picture) is in the works resp. ordered - it will look like V5.1.3 and have only minor changes (e.g. CPU-Board and Antenna optimization)
PS: the backside is not that interesting - it shows the keyboard maeanders right from the beginning.