I recently sold both my 18" WSM and my 14" WSM because I had not used them in about three years. When I first got the 18" one, I had great success with it with minimal effort. Later on for some reason using the same techniques and charcoal, could not keep temps up for anything and is why I quit using it.
While I have not smoked anything with my 22" kettle or Performer with the SNS, I would probably still prefer it over the WSM because of how frustrated I became trying to use the WSM.
I have other brands of smokers with a lot more room than either an 18" or 22" WSM that hold temps without messing with vents so I don't miss not having a WSM.
Wayne