you should use this opportunity to blow away acdsee.-superboyac
As I read the OP, it isn't intended for that, but as a fast convenient helper for other programs. I really like the virtual folders by date, and it's commendably fast. Mouser's Media Browser has some useful features, but I find it odd that you access them from the thumbnail, rather than the larger image. Also it calls Windows File Explorer, which is never going to be my favourite file manager. It would be nice if it could pass the file name+path to whatever file manager (FM) you specified. Failing that, a very useful feature in Faststone Image Viewer is the ability to press [C] for [Copy an image], and have it pop up a dialog of target directories, see screenshot. That cuts out a lot of the need for an FM.
Acdsee is slow though. Everything is just kind of sluggish.-superboyac
Don't overlook that
WinCatalog can catalogue image files and store thumbnails. It's pretty quick at indexing and very fast at displaying and browsing, though again it calls Windows File Manager for file management functions. The database can be quite large.