I've got a 9 year old Weber Q (full size) that's still purring like a kitten. Haven't done a thing to it except clean it once in a while.
The Qs fall into two categories; the full size 200 series, and the "baby" Q, 100 series. We love our full size Q but be aware that it is HEAVY compared to some grills. Built like a tank. Some like the baby Q better because you have a better chance of stowing it in a side bin, but I like the versatility of the full size Q in case we're cooking for several people, which we often do. Whichever one you buy, also get the rolling Weber cart made for the Q. Same cart fits the full size and baby. You'll appreciate the cart for sure.
Like the member posted above, we bought an Extend A Flow kit and run the Q off our trailer tanks. Some folks run 'em off the 20 lb bbq tanks.