The 1900 has a multi-point auto setup compared to the 863's single point, which seems to give it a more detailed, better balanced presentation. If you can stretch to £1,000, an extra £125 will get you the 3900, which has a much better menu system with greater setup flexibility, including multiple crossover points for individual speakers rather than a single crossover point. With the network features and internet radio, it's a much better value for money amp than the 1900. Like I said, I've just mentioned it as it's a little bit more.