Here's Callaghan in the Tribune:
Tuesday’s apparent change of government in Federal Way, from council-manager to strong mayor, might trigger another look in the state’s third-largest city.
If the majority holds in Federal Way, three of the state’s 100,000-people-plus cities will have strong mayor and three will have council-manager.
Federal Way will join Seattle and Spokane with mayors who run the city while Tacoma, Bellevue and Vancouver will have mayors who chair the city council. In the next rung down – cities with populations between 50,000 and 100,000 – six are strong-mayor cities and six are council-manager cities.
And Exit133 asks a salient question, "Does it even matter?"
For reference, here's my post asking the question after the Luzon.
And the City Club of Tacoma study about this in 2003 (PDF).