I have to admit, it would be nice to reply just on one photo editing and viewing program to manage my photos.
The problem at the moment is that I use Picasa for uploading but not for editing or management. Visions is designed to try and unite all the most important photos editing and managements tasks in one program, mainly viewing, editing and sharing. Editing photos is very simple in visions and the feel is really professional and solid. In particular, the program outs a heavy focus on the right tagging of photos via it's advanced Meta (EXIF) editor. The problem or advantage, depending on whether you use it regularly, is that the only way you can share photos with Visions is via Flickr so like it or not, you'll need a Flickr account. But what really shines out with Twins Visions is the 3D viewer which allows you to view and manage your photos in 3D. Via the 3D showroom, you can navigate through your folders, run slide-shows of your photos, manage your albums, perform quick photo collection tasks and execute advanced search queries on your collections.
This is an immensely attractive and powerful photo management/viewing application. However, it does require a Flickr account.