The only drawback I see is the bank transfer thing. I know it's acceptable in Germany, but for the UK and other English speaking markets, they need to offer PayPal or credit card payment options.
I'd like to keep the group set cranks for my Serotta, and P2M don't do Shimano or there would be no issue, but as it stands I'll grab some p1's when I am in the U.S. next
They dropped them just before Eurobike.