OK, my 2 cents. I started out with one 18 for just two of us. Then needed one more because having friends over or friends wanting me to cook for them one wasn't enough. Ended up getting a Backwoods Fatboy to be able to even put more meat on. This thing grows on ya. Then comes the high temp brisket and putting on a 15 #'r and figuring out how ya have to foil the ends to keep from burning. Then having to do 12 racks of ribs with just the two 18's (I know can be done). Now comes the 22 (R4D4). Brisket fits. 12 racks of ribs (using rib racks on both bottom and top grate) without having to bend the ribs. Now I haven't done that yet, but certainly possible. A whole package of 24 chicken wings spread out only on the top rack (that I have done). A whole pork loin (3 pieces) spread out only on the top rack. A turkey should probably fit better. It just goes on and on.
I got rid of one of the 18's and now use R4D4 primarily just for my wife and I. Have to force myself to use the 18 just to keep the yukkies out of it. Plus, when I cook I'm always doing more than just the current meal. Ya have to have lunches for work too.
A friend of mine just picked up a 22 at WalMart for $299 (sorry Chris, but I did order mine through here as well as all Amazon purchases).
Yes, we also do competitions and am looking forward to using the 22 for them (did use for Fire on Ice). But even without doing competitions I am glad R4D4 is here. You just need to think down the road when you say to yourself "I wish I would have gotten that 22".
Dan