I have used the "Clipboard" for about a week of use now. I have found a couple of things I would change.
I would put a little separation between the half board and the full board. The T-cobbler overhangs the half board when it is plugged into the full board. If you wanted to have two projects, one on each board, you might interfere with the one one the half board.
I would put the RaspBerry Pi closer to the top edge of the clipboard. This would make it easier to remove the SD card. Putting a divot into the board, similar to the Pi Dish, would help also.
Having two Solderless boards makes it easier when you want to have a complicated project. I plan to have a ATMega168 on the half board and carry out the wiring to the full board. That means you can wire setup the ATMega up, capacitors, regulator, programming switch etc. and still have plenty of room to figure out your project connections.
A couple of tips:
Pre-thread the board edge mounts before you use them.
Layout your boards and RasPi before you mount anything, make sure they do not Nyerere with each other and that the cobbler will reach both boards.
Raspberry Pi Projects:
Wordpress site on Raspberry Pi
Unified USB Hub and Raspberry Pi