The post "What I Hate about my Prius" stated that the cloth used for armrests looks terrible after a few week use and after two years the center armrest is threadbare. I don't know what year Prius was involved or if the fabric upholstery is different in the 2006 model, however, I would like to hear user's experience with the fabric instead of the leather.
I have a 2005 with 24K miles and have had it one year. So far the arm rest is holding up okay. I'm a runner and have had some sweat issues at times. I try and keep it covered after a run but I'm not always successful. I expected it to wear but have been pleasantly surprised.