Here are a few things you can do to speed up the CP in 2.0. This may not work for everyone, but I’m experiencing 1.6 like “snappiness” in 2.0 after making these changes.

Admin > General Configuration - Disable “New Version Auto Check”

Disable the Expression Engine Info Accessory

If you are using NSM Updater, disable it completely, or for every page except the home page.