*snip*

Running two work units simultaneously will not lead
to the improvement you have predicted.

I don't see any prediction other than running two at once will slow
down your times but increase your overall production and this is most
certainly accurate information.  That 3.0c should be turning out about
15-16 wu's per day if the user dumps the GUI and switches to the CLI.

I'd recommend running SETISpy and SETIDriver with the CLI.