I purchase my Weber Sprint Grill in in the Summer of 2014.  I use it every week all year long.  Finally the Flavored bars had holes burnt in them.  You could see the flames through the holes.  The replacements work great!  Would reccomend to anyone who grills a lot.  The fat leaks out of the meat and lands on the bars. The fat smokes adds flavor to everything you cook from fish to chicken to steaks.