I have the Elite model which is one down from the current model GT. I am not sure about the XS. I have found several locations on the web talking about operating tips for the XS. I just typed in Minelab Sovereign XS on Google and found a good bit of things that people were eager to share. I can tell you one thing. I have been happy with my Elite so far with just the stock coil. I bought the 15 inch WOT coil also for mine but have not been too impressed with it in the early going. I am still in the learning phase with the WOT coil though so I will hold off of a detailed critique of it until I have some hours under my belt.
I believe you will like your Sovereign in the wet sand and on the beach. It is really made for that environment and does well. I just haven't put mine over any tickets yet to be rewarded I guess. I did some early hunting at a couple of Elementary School playgrounds and it tested out fine there finding lots of stuff that many others had missed. I was really impressed with the depth of the stock coil.
Good luck in finding some information. There are probably some folks on here that used that model for a while.