I do not have the XS but I know some members put it on here and enjoyed it, personally it wasn't near loud enough so I was not interested in it. I went with the ATAK, but its loud so you need to like that note.
Drone wise you will get some with all Borlas, but it varies, and what you do with the flappers will also dampen the impact of the drone. Some members kept both in, some removed 1 (usually the downward flapper) or like me, removed both. From what I've heard leaving both in will have large impact on drone, but also impacts exhaust tone. I removed both, I love it, but do experience a little drone but only at certain speeds otherwise very little impact. If I was to offer advice generally from what I've noticed many members suggest who do not get full catbacks, it appears removing the forward flapper is the way to go. If you want loud, then remove both. Hope that helps