Done which one? I've got a 3" body lift (on a YJ) and I personally have not experienced any cons. Some have said that they had to adjust the fan shroud, extend brake lines, etc. The main pro is that you then have more room to rerout your exhaust and everything else up higher, out of the way; and, that it is a cheap way to gain tire clearance. I don't think there are any cons to the spacer lift.