We've been ICPI certified for 6 years now. Most of the larger manufacturers are starting their own "certified contractor" programs and are requiring contractors to be ICPI certified and some are even pushing NCMA as well. These programs are nice, because it's another notch in your belt plus they send you leads here and there, Certification is worth every penny and every bit of your time. It adds professionalism to the industry and increases the quality of work out there. Maybe one day we can get away from the old "pavers always tend to get wavy" stereotype.
Chris