Another plug for the YMCA. +Plus is worth it for the towel service (except maybe eauclaire, i think it costs more there for some reason).
As for the north hill WHC went to go tour it a few months ago before I committed to the Y. Went right after work, 5ish? And it didn't seem overly busy. busy, but not crazy, minimal wait for equipment.... worth a tour, i felt it was kind of small and congested? Just don't give them your real phone number... the sales pitches keep coming.
The NW needs a leisure center

Unless there is already one and I don't know about it.