One of the reasons why you might have trouble finding fanfic for it, is because it is often bundled with Tsubasa Chronicles, which is a better known series. (Canon, Clamp crossovers, XXXholic is sometimes slowed down to coincide with Tsubasa events, one of the major characters in XXXholic is a significant character in Tsubasa.)
100% your choice just I had to take off the communities on my flist because they were *too* active (and the things I was interested in was lower than the things I wasn't interested in...) so was a little surprised to see it here. ^_^;;