We have a 23" Ultimate KK, and a small Weber I sometimes use for preheating my smoke pot. Our neighbor has our previous K7 ceramic cooker, and a wide selection of other cookers including a pellet smoker, one of those South American grates that goes up and down, and a wood fired pizza oven.
I'll go out on a limb and say one can only achieve pizza greatness in a wood fired pizza oven. One can also lose a pizza in a blink of an eye; constant attention is needed. I also have experience with various roadside wood fired pizza ovens; a stand between Salem, OR and Monmouth, OR comes to mind. In general, a smaller wood fired pizza oven than a restaurant in Italy would choose saves fuel, time, space, and money, at the expense of the pizza. While I'm completely happy with my 23" KK and wouldn't change it out if I inherited another comma; my neighbors are already plotting a size up for their wood fired pizza oven. It's very simple: In a too-small oven, the fire is uneven, and the pizza needs frequent fiddling and turning. A larger oven is more stable.
If one knows one's KK and one's pizza recipe, and has a good sense of one's fire, one can pour wine at the table like there's no tomorrow, armed with only a timer for retrieving a credible finished pizza. The main issue with the KK (once one learns to get a hot enough but not excessive fire) is that the heat comes from below. I like using the KK double-walled drip pan as a heat deflector, to protect the KK pizza stone (as good as a Fibrament stone, and it fits) from radiant heat from the fire.
For a wood fired pizza oven, go big or go home.