I had to transfer more than 600 VHS tapes that were mostly commercial tapes to get them onto a DVD. I was up against the same difficulty as you -- I could assume that most would have either Macrovision or CopyGard.
I purchased the following -- it is a budget "time base corrector." It handled ALL of these 600 VHS tapes, with no problems.
Click here to see the $190 Time Based Corrector.
In my case, due to the fact that I did not need to do editing, I decided to dub directory to a standalone DVD recorder. However, the device definitely worked, on every mainstream tape (including many Disney) in our family's sizable collection. This 8 month long project went smoothly, with the above device.
I had read that the Sima units would work with SOME of the various forms of copy protection that were used on VHS, but not others. I read this was even more true of the lesser expensive Sima unit.
Thus, I spent the extra money, and I am glad that I did. It also cleans up some of the errors inherent in video playback. It can also do some correction of color / chroma problems, where you find them.