From my understanding, you can recover data after a wipe if that data is on a sector that has been marked as defective by the firmware. A software wipe will skip it, but "SATA secure erase" should not.

Another thing worth noting is that hard drive manufacturers intentionally make recovery of overwritten data difficult. Not because of security, but because data that can be recovered is wasting space. For example, if you have a 100GB hard drive and you can recover 10GB after a wipe, it means that there is actually 110GB stored here, and the manufacturer will want to tweak things up to make used of that space.