update location metadata in photos

I'm concerned about the base location metadata that the new mac photos app is pulling in.

The information is often recorded wrong at the source. Photos from Facebook seem to have the location of the server. Photos taken from different cameras/phones have different settings and thus get sorted into different "batches". The GPS can also be wrong by a few feet, moving the photo's location to a different address than it really was taken at.

All of this was easy to fix in iPhoto but seems to be impossible in Photos. Is this going to be in an update or has anyone tried a third-party?

Thanks,

Robert