Quick tip: OpenSubdiv performance

Use Subsurf with OpenSubdiv for all the objects in the scene, to keep high performance results.
(Even if you don't needed )One or many objects without OpenSubdiv can slow down drastically other objects who will use OpenSubdiv. (depends by polygons, number of objects and hardware)Also the number of subdivisions need to be set 1 or higher, to make use of OpenSubdiv. 
And Optimal Display can improve the playback with some fps as well.