Recurring window manager performance issues in 10.10.x

I've been having graphical performance problems with Yosemite since early developer previews. The main expression of this is trying to switch applications. When going from Terminal to Messages or Adium or any other application that has a text entry field, it is readily visible that the app is very slow to respond in allowing the user to actually enter text into the field. There is a 1.5 to 5 second delay each time one switches between such apps.

This is not an issue in Mavericks and after having spoken to some other developers, there is a known bug in the Window Manager that is causing some serious performance problems, but I'm not sure if it is this precise problem.

Has anyone seen this issue and / or been able to resolve it properly?

The only thing I have been able to do so far that seems to mostly resolve this issue is to go into System Preferences -> Accessibility and turn on Increase Contrast. Once I do this, applications seem to be fairly responsive again, but this is a very troublesome issue for a few reasons; one of which is that some system UI elements are visually unappealing and hard to read (yes, funny when this is supposed to help, but buttons are particularly affected).

I'm running 10.10.2 on a Mac Pro (Mid 2010) with 48 GB RAM and an ATI Radeon HD 5870 (1GB).