It was a brilliant stroke last spring when the Robischon Gallery, the city's flagship, presented two sculpture shows, John Buck and Manuel Neri, and installed them back to back. The show illustrated how the two artists compare and contrast with each other. Both are masters of contemporary sculpture who work in the West -- Buck lives in Montana, Neri in California -- and both do pieces that incorporate the human figure. But each is unique: Buck likes a lot of extraneous details, whereas Neri is into simplification. The thoughtful placement of the works at Robischon enhanced the whole experience.