I can't say that I'm very impressed, though. The case consists of two "U"-shaped halves, which clip together to form a closed case. For many electronic projects this is a tried-and-tested design, but it works best if all the cut-outs for sockets, knobs and stuff are on one half of the case, and there is a bit of room around the board for access and wiring. That way the board can be secured in place, yet the case can be easily opened for modification and maintenance. This combination of a Raspberry Pi with a PiFace Control and Display fitted requires cut-outs on five of the six faces of the case, and almost all of those have protruding sockets or buttons. This means that the case needs to be bent alarmingly out of shape even to get a single board in place.
I just about managed to squeeze my red Chinese Pi into the bottom part of the case, but had no end of trouble trying to fit the delicate-looking protruding buttons of the PiFace Control and Display at the same time. I tried fitting the PFCAD to the Pi first, then put the Pi in first and tried mangling the case to get the board in place and on to the GPIO pins at the same time. Eventually I abandoned both approaches as I was seriously scared of damaging the Pi, the PFCAD, or both.
In conclusion I can't really recommend this case. It's a nice enough idea but it simply does not seem practical, especially for the price of £13.78, almost as much as the PFCAD board itself! I would have been much better with a PFCAD version of the cheap acrylic "jigsaw case", or better still, a new design from the clever people at ModMyPi or Pimoroni