I run a 14 inch Smokey Joe, thing is great for doing sides on and is very portable when going out camping. Use it all the time. I have had it for years and consider the 14 inch a must have, not a lot of real estate but is like a side burner on a gas grill
An 18 inch silver that I have converted with the ash bucket and a grate that flips up. Those options are really nice, and worth getting the top model for. Anyway the 18 is my steak machine, or whenever I want direct cooking. I have a set of baskets for it also.
My 22 inch is a masters touch, all the bells and whistles. worth every penny if you ask me, after getting it I upgraded the 18 inch as I saw the need for the upgrades I did. plus the MT has the insert system, I have bought 2 inserts that I really like. The 22 inch MT has a lot of real estate. I do my smoking in there can do 3 racks of ribs easily on a 5 hour cook. If you only wanted one kettle it is the one to get.
I will be getting a 26 inch soon, to ease my smoking, I want the extra real estate.
Mostly it is up to your personal ingenuity with the sizes, I have seen guys doing great indirect cooks on 18 inch grills. the 14 is a bit small for such, but then you can use it with out a lot of coals for small dishes.
But Yes I feel the premium models, weather called a gold or a masters touch or whatever, offer options that you will find very nice. And will admit were worth the money.