If the arranger is not flexible i.e if i need to use additional hardware like a computer to edit sounds, sequence, or create and modify styles, i wont buy it. It has to have good pianos and drums and guitars and brass. If its awkward to navigate around i wont buy it. And if it does not have internal speakers i am less likely to buy it, but its not a deal breaker. It must have a lot of modern styles as well as great jazz styles too. And if the build quality is poor (is not durable and would crack or get easily damaged when carting around) i am probably not going to buy it.