I have hunted with other hunters who use the XLT on the beach and it seems to do fine in the dry sand. They use it also in the wet sand but seem to have problems with it there although there are program set ups for it to deal with wet sand. The bulk of the folks I have seen with it at the beach have been sticking to the dry stuff.
I am a White's fan because my first two serious relic machines were White's. I bought a White's 6000 Di Pro when they first came out. People will tell you today that they are still worth their weight in gold. Then I bought an Eagle Spectrum. Both very fine machines.
If you plan on hunting a little at the beach and lots of places elsewhere, I would say go for the White's if it appeals to you. If you are looking to hunt the beach mostly, I would say to steer towards the beach machines made by Garrett, Minelab, Tesoro and Fisher.
I use two brands, a Garrett Infinium for water and a Minelab Sovereign for the beach.
Good luck with your choice.
Jim