Cards, Is It All It Could Be? Apparently Not...

"Introduced alongside iOS 5, Cards allows users to produce and mail made-to-order letterpress greeting cards with nothing more than an iPhone or iPod touch. Sounds pretty slick right?"

Indeed it does sound slick!! Apparently though, it isn't as slick as it first appears. But I do like that you can send a complete card postage included for $2.99 USD. They seem to have issue with the fact you cannot use iTunes account balance and have to use credit card, but that doesn't bother me too much. They also feel it is unpolished, but from what I have seen it isn't too bad. However, this is coming from someone that hasn't used it. How about you? Have you used it? If so what are your thoughts? Or have you used something similar with better/worse results?