I wonder what exactly is the stock ride heigth on a brand new XI? It's problably somthing like the 4 finger gap that I had before putting on the Pro kit (or a little lower because of the stock shocks and not HD's).
I don't think the height that I'm at now is too odd because the Pro kit did lower my car about 5/8 of an inch and may settle futher (it's only been 3 days). Pro kit is advertised to only give like a 1-1.2 inches of drop. I've seen others report no visual lowering right after intstalling the Pro kit but then get a decent drop after a few weeks.
I could still put on some lowering perches if it doesn't settle any. I went with the 'I' tophats when I replaced mine, so they will fit even though mine is an XI.