PhotoPost has a much deeper intergration with vBulletin than Coppermine which has to be modified to integrate at just the user level with vB
Both PhotoPost Pro and PhotoPost vBGallery integrate into vBulletin - not just sharing the user database. You get signatures, avatars, vBulletin's data entry boxes, etc. PhotoPost vBGallery shares vB
's template and phrases system and integrates directly into the Admin CP.
So, if you are using Coppermine bridged to vB
, you are missing alot.