It is really simple. The money arrives into your account within 10 days. The charge is 2.75% per transaction.
We have all recently answered a survey regarding our use of it and I would think that everyone will have said that we want the money to arrive quicker. So hopefully they will be able to do something about that.
Other than that I can't think of any problems with it. It's always worked perfectly for me. Only had one client whose card was refused. After her blaming the izettle, then she went for cash, turned out that she had overspent on the card she was using. Her husband apologised for her, as she was rather rude. She's ok now though.
I don't have many card paying clients so having a contract machine would be a huge waste for me.