We had 62,000-some digital assets when we installed Portfolio in 2013 - mostly photos. I'd been wrangling photos from multiple sources, and our users had been renaming files so they could record the details of an image. Extensis Portfolio made it easy to assign keywords, captions, and other details. I like being able to quickly create a gallery of images and generate a PDF. I also love the ability to batch rename files - or resize. We recently added the NetPublish feature to add the ability to share galleries with others within our network who don't have access to Portfolio.
We now have multiple catalogs (one for marketing photos, one for events, one for archive, one for confidential) and our users want to be able to search across the catalogs. Our users also seem to have problems with search requiring quotes around a name. (Otherwise, a search for John [space] Smith returns all photos tagged with John and all photos tagged with Smith.) I wish that if I chose to move a folder from one catalog to another, it would move the folder itself and not just the assets inside. The zoom is not as clear as the one on Adobe Bridge, so it can be hard to read peoples' name tags, for example, which would be handy for tagging. I have a bad habit of logging in and doing a search, and then closing the browser window and needing to start over, but I don't know how Extensis could fix that. I liked the product better when it had a desktop version - it was easier to link images in InDesign. The web-only option can be frustrating. Lastly, although this is great for photos, I expect there are better products for managing video.
This may not be the most sophisticated product out there. If you're looking for something to manage video, this is probably not the right solution.
We work with photos from across an entire academic health center. Extensis Portfolio helps us find, organize and tag files and is especially helpful when we need to remove a photo from our collection. It's helpful for tagging subjects so we know whether they are a patient, a model, a volunteer, etc. We purchased it to help manage patient photos and releases to make sure we weren't violating HIPAA law.