Good question! I want to say I've actually seen a tad bit of oil leaking from mine, but the suspension still feels tight with minimal body roll. :shrug:
I guess I'm the outlier here. I had a 2003 Sport with 237,000 on it when I got rid of it and XREAS was still good. I'm currently driving a 2010 Limited with 221,000 miles and, once again, XREAS is leak free. I'm going to be pissed if I just jinxed myself by responding to this post!
In both cases, used as daily drivers with the occasional snow storm thrown in, so maybe that has helped the system last longer...