You need Sentinel to keep the database up to date, plus, if a firmware update is released, it has to be installed via Sentinel.
You can install ProScan, & use it for programming, without deleting or uninstalling Sentinel. There's no problem having both programs on your PC. ProScan will not overwrite Sentinel, but you can use it to edit or create Favorites lists instead of Sentinel.
You're a Premium Subscriber. If you are loading a large regional, or statewide, system in Sentinel, when you append it to a Favorites list, it brings along all of the sites for that system, many of which are well out of range. But, in ProScan, you can do an import from RadioReference, and select only those sites & departments that you want.