I have it. US comp'd me a year's membership when I hit 120 flights on the year. Depending on which lounge you will frequent, the seats are just way more comfortable and less people traffic to deal with. Not much on "real" food, but there are snacks available. Free Wifi, plenty of outlets to recharge your PEDs. Also if you need to do work, there are private areas to set up shop.
I also value my membership to get into lounges in star alliance.