You are essentially sacrificing your product's value for word of mouth.
He very clearly mentioned that the response has been more warm and positive than negative. So it seems obvious to me that they are not sacrificing their product's value at all.
"He very clearly mentioned that the response has been more warm and positive than negative."
Maybe that's true so far, but I suspect the early-adopter users are more forgiving of a lot of things. The hockey-stick users might be less so, and IMHO they need to be looking forward to those.
He can tout that all he wants, recipients of cards aren't going to be giving direct feedback and the sender is going to be thanked regardless. Having 'made with iPad' cheapens the card anyhow, throw your brand on it, and stop being greedy.
You are essentially sacrificing your product's value for word of mouth.