I have about 3000 rounds thru an XD40 and about 1000 thru an XD9 with zero failures of any kind. The XD9 is my car gun and has survived the heat/humidity of summer and the freezing cold of winter with no problems. Not an extreme test by any means, but good enough for me.
On the guide rod issue, I replaced the stock guide rod with a one-piece Don's guide rod and spring in both my XD's. The gun will fall apart before that piece of solid steel breaks.