I've tried the Taptation once. Didn't like it. I've got a spare pair of the taptation chips. You can have it halfprice if you want?
The tap works. I don't suggest trying to change tempo while playing because the delay time jumps while you're at it and it takes about 1-2 seconds for it to lock in the tempo after tapping it. The modulation sounds great but the depth pot should be a MUCH lower value as it goes way too deep to be usable.
Here's a video of the one I built:
YouTube Link
www.pedalprojects.com
www.facebook.com/pedalprojects