When I bought FoldersSynchronizer I thought I'd use it to sync a folder on my MacBook Pro with a folder on a large flash drive.

Then, I discovered it is an EXCELLENT tool when trying to recover data from a damaged drive. I do a lot of data recovery and FoldersSynchronizer has worked great as a way to repeatedly scan a damaged drive, harvesting any files it can and ignoring files it has already successfully recovered.

Now, I'm using FoldersSynchronizer to sync the documents folders on my MacBook Pro and my Mac Pro. I like previewing what it's going to do before it does it. This software is rock-solid (in my experience) and I highly recommend it.