The three pedals, soft, sustenuto and sustain work as expected and well with the P105. Sounds good and makes it feel like a proper piano! Very easy to put together. However: there were no instructions (I could find) that told you how to attach the unit to the sides. This might have confused *some* people I have met who seem to have trouble with ikea stuff. It was pretty obvious though, remove the four grey plastic hole covers and use the four large screws the pedal unit came with. I located the holes by holding the pedal unit maybe 1cm off the floor and poking the screwdriver in; then pushed the screws through to catch the threads. Also the cable from the pedal unit to the only had three cable clips; I think it could have done with 2 or 3 more.
But overall very nice addition to the P105 bundle. Looks like a nice clean piece of modern furniture as well (just hope the new puppy does not decide to chew it!).