I am finally getting good results with Thorsten Hartman's render optimizer script:http://www.infinity-vision.de/blog/render_optimizer
I used unified sampling with settings of:
If you try this, be sure to embed the settings in the file under the settings tab. Otherwise network rendering will not work.
My rendering time is still too long, (20-30 mintes/frame on my 6 core xeon workstation vs 40-70 minutes/frame on my older quad core xeon rendering machines) but at least it doesn't flicker any more.
I haven't played around too much with final gather yet. What has been working for me is using "from camera position" method, 1 file/frame, interpolate for 2 frames.
I will put it up on you tube today and provide a link. It would be nice to get some feedback from forum members on how to improve the rendering or even optimize it further to render faster. For now I am including the first frame of the animation.