New, cleaner, more intuitive user interface. Good for locating potential funders and grant opportunities, big or small. Worth the investment.
We have a niche mission as a nonprofit which translate to competing for very broad grants or finding very specific grants. FDO does a good job of being able to locate off-the-beaten-path grant opportunities thanks to it's very flexible search function and a huge database. We are able to do research for grant opportunities, like-minded foundations, similar past grants and their recipients, past IRS Form 990s, key personnel, etc.
Similarly helpful is being able to keep all the research straight in a workspace, a workspace with a workflow interface. It's where you can list tagged foundations and steps you through stages of proposal development and submission, entering work notes along the way.
Our first grant we ever received (and the first grant we ever applied for) was through diligent research using FDO to identify likely opportunities and then homing in one one "most likely of success" grant.