Grab the XLS if you can- APU and most likely your legs will average under 2 hours. The Sovereign is a nightmare with all of it's capabilities (great for the customer, but it can do almost anything and you will have coast to coast flights in a fairly small cockpit at slow speeds). The XLS can hit the short runways, but you will rarely get 4 hour flights versus 6+ hour flights that the Sovereign can do.