I'm about to recommend What Have We Learned? (Abingdon, 2001), the latest compilation of genius by that master technician of church mechanics, Lyle Schaller. But not yet.
I wouldn't recommend it for its carefully stated and masterfully supported unifying theme. I couldn't find a theme. There's something about forty years of astute observations of church life, but not enough to sustain a thesis.
I wouldn't recommend the book for its theological integrity. It is far more sociological than exegetical. Schaller shines brilliantly in understanding the nuts and bolts of how churches work, but he will win no ribbons for ecclesiology. I even found myself in rare disagreement with Schaller in his section on denominational oversight of congregations.
Yes, I'll recommend the book, but not for its disciplined approach. Schaller will give you a swarm of reasons when a handful would make the point, a list of 44 when 4 would do.
And my recommendation won't be for Schaller's elegant style. Schaller writes ...1