Remove common of 150000 pages on a 1.1Ghz cpu should take a little under an hour if it's the only thing running on the system. I would expect the process size to be between 100 and 200 megs.
I have similar issues -- "removing commonality" takes a long long time. Question: how exactly do you turn that option off? Is that the same as the "prevent duplicates" setting?
Thanks- N