Lightroom is billed as a catalog for photographers. If a photographer takes a photo into PS and makes a file larger than 4gb, then LR4 will not allow it to be saved back into catalog. With large panos it is easy to exceed 4gb. This forces photographers who work with larger files to save and track these photos separtely, thus making the catalog incomplete. PS can handel the larger files, so LR should save and catalog PSB files as well.
