There are many things I like about Portfolio. When evaluating different DAM solutions we found that Portfolio had the features important to us while fitting our budget. DAM systems can be extremely expensive and prohibitive for small businesses.
Having the ability to maintain our basic folder structure with the 'watched folder' setup was important to us since we had our own system of organization. But other features were even more important—like the ability to map metadata to custom fields and include enclosing folder/file names as keywords, for example.
As a user, I find the QuickFind field with predictive search as well as the more detailed search capabilities quite powerful. For our assets and file naming convention, using QuickFind usually is enough to bring up the selection I need for most searches. But, digging deeper and refining a search is easy and intuitive.
Another feature I find very useful when collecting images for a project is to flag of the images I want to select for download. This collects them in the "Flagged Assets" gallery so you can download them in one zipped file instead of downloading each file individually.
Smart galleries are also very handy since you can add photos from your catalog to a smart gallery by simply adding a keyword or phrase, for example, depending on the field used in the saved query.
And, thinking long-term asset management strategy, scalability is important to consider. Portfolio can grow with your business through add-on module licensing. We recently added the Smart Keyword module which has improved our search efficiency and, for the nerd in me, is actually fun to use. Review collected by and hosted on G2.com.