I have a question along this same line.
I'm an event photographer and have been using Coppermine, which allows me to maintain separate directories. I like this but am looking for tighter integration with vBulletin and therefore am considering vBadvanced Gallery and Photopost. vBa Gallery puts all images + generated thumbnails into a single directory based on userid. I don't like this, as I'm concerned with perfomance when there are, say 100,000 images in a one directory, not to mention the organizational mess of having all files in a single directory.
Can you tell me if Photopost will allow me to maintain a directory structure, ie each event in a separate directory?