Thanks for all the suggestions. I'm still trying to make up my mind.
In addition to the 22" WSM I do also have a 22" OTG. I've used the OTG for PSB, wings, high heat (indirect) chicken), and very occasionally for ribs, but mostly it gets grilling action. It's just so much easier for me to control the temp on the WSM vs the OTG for cooks longer than an hour or two.
My practical side says, "Go with the 14" WSM, it's less expensive, more portable, and all you need", but my BBQ head side says, "Go ahead for the 18" WSM, it's not that much difficult to transport and can cook more food." We'll see which side wins out.
I have seen a few 18" WSMs on Craigslist for about the price of the 14". They seem to be in varying states of condition and old enough that they don't have the temp probe silicon grommet. My 22 WSM doesn't have the grommet, but It seems useful.
How many of you with the grommet model actually use it?