BB Boss shows you the size of your Java folder in the status bar at the very bottom. Open it and check. I believe I shrank 7.0.0.440 from 164MB down to about 62MB.
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you could always go into the OS folder on your computer and check the size of removed cods folder and compare it to the overall size of the whole java folder. simple subtraction will yield your answer. however, this wont necessarily reflect the size of your os on your phone. that will depend on what options you chose to install.