This setup eats your freshly created files if you forget to run the rsync command before switching to the other computer. Not so nice. Unison [1] can avoid that problem by having some state on each side. Therefore, it always knows whether a file was just created on machine A or whether it was deleted on machine B.

Everything else is almost the same with Unison compared to rsync. There is no P2P overlay network, everything goes through ssh. It uses the rsync algorithm to optimize the transfer of changes. It is run at specific times, not always in the background. Therefore, you know when synchronization is happening and when it is finished. Unison also has rules to map different path on each side and you can exclude by path, filename, and suffix, etc.

[1]: https://github.com/bcpierce00/unison

I've got concerns about the --delete - since you're copying-with-delete from desktop first, it automatically assumes that anything you put in /home/me on the mac is going to get blown away.