I'm having fun with my 14.5 WSM. I had bought a used 18.5 WSM and got it all cleaned up, figuring that was the best "middle of the road" choice. The grates were rusty, so I replaced them with KillaGrilla stainless steel grates. Also added was the Unknown BBQ SS hinge, Arbor Fab charcoal basket & minion starter and Fireblack gaskets for door and lid.
I then found a used-once 14.5 on Facebook Marketplace for a good price, so I jumped on it. It cleaned up wonderfully. It got an Arbor Fab basket / minion, hinge & gaskets. I have also gotten a Hunsaket hanger and FireDial that I haven't used yet. I have been using that as my "starter" or "training wheels" with chicken and chuck roast so far. Big fun. I use my Thermoworks Smoke X2 for pit temp and meat temp.
I just found a used 22" on marketplace for a very low price, so I'm gonna go look at it tomorrow.
While I'm getting that cleaned up and re-fitted for future brisket cooks, I'll be working the 14 and learning the ins and outs of BBQ and smoking at a lower fuel cost and hopefully more simplicity.
I doubt that I'll ever "outgrow" the 14 for the two of us, but I'll have the 18 and the 22 for the bigger stuff when family, etc. invades en masse for holiday functions. I have a Signals + Billows for all that stuff.
I wouldn't rule out the possibility of having all three of them going at once. LOL! I suspect the 14 will always be my go-to for household food, tho.