There is no Pro version of Uninstall Tool, it's a paid product. Of course as you mentioned and I was already well aware of, there is a free version called Geek Uninstaller. As I explained in my last post Uninstall Tool is fully functional as a trial for thirty days. It has the exact same functionality as the paid version, so obviously it doesn't matter if you are using the trial version of have purchased a license, the results will be exactly the same.
Here is the features the Pro version of Soft Organizer has that the free version doesn't.
Soft Organizer - free program uninstallation utility.
www.chemtable.com
None of those features are related to the scanning of leftovers. So once again, there will be no difference in results between the free and paid versions.
I was only testing the scanning for leftovers and not using the snapshot functions which keep a record of every file and registry key added when you install software. However, based on my testing and I did test every installer with monitoring three years ago, I found that Total Uninstall was the best in that regard. That is why I purchased a license. I would have preferred to use something that was cheaper or free, but it seemed to do a much better job than the alternatives.
Of course you are free to do your own testing and reach your own conclusions.