Did you order it with an accessory coil? What types of sites do you plan on searching? If I might ask, what were the factors that convinced you to get the XLT?
As for Garrett's Ace 250, I have owned a pair of them and found them to be quite good for the dollar. Better than most of the competition in that price range or a little more even. Unfortunately, I live in an area with very high mineralization and found the factory preset ground balance of the Ace 250, much like many of the competitor's preset models, to be set a little negative and thus it has some problems. Falses a bit too much in some areas. In low-to-moderate ground, however, I was impressed by the depth of detection.
Now to the XLT. This one of my all-time favorite models! It offers a lot of potential, it can be fun to use, and the overall performance (with a custom program) can be a real pleasure.
But you made a comment that concerns me: "Looking forward to finding some deep stuff after awhile for sure."
It concerns me because I've known many people who have bought upper-end models through the years thinking that they would provide an impressive increase in depth. The problem is that their perception of "depth" and how deep they think good targets are is a little errant.
On a positive note, you did qualify your comment by saying: "... after awhile ..." and that suggests to me that you're aware that, in time, you will learn and master the XLT to get more out of it. That's good. All too often buyers think that the simple purchase of a high-dollar model is all it takes to get older and/or deeper coins and goodies.
Enjoy your XLT. Don't rush to adjust everything. Some of the functions should be adjusted to improve performance, and some ought to be left unchanged. Some can be improved with a little adjustment, but a radical change of some features can have a negative impact on the XLT's performance.
Other than a quality set of headphones, the best accessory I feel you could own is a 6