Over xcompmgr, Compton does allow for page-flipping to yield tear-free screen updates and it also provides unredirection of full-screen windows to get page-flipping directly from the OpenGL app without an extra copies. Broadcom developer Eric Anholt has also provided some recommendations to the Compton developer for better optimizing its performance for tiled-renderers like is common for ARM devices. He thinks some tiled renderer improvements could "improve its performance for windowed updates significantly."
Compton isn't yet the default on Raspbian but expect that change-over to happen soon. VC4 developer Eric Anholt shared these details in his latest weekly blog post. In there he also shared the latest work too on multi-threaded fragment shaders.