Is there any disadvantage in using SSHFS instead of SSH alone?

SSH is not primarily used to copy files. It's used to log in to and operate remote machines/server via a secure link, and create secure tunnels between hosts. It's available (or can be installed) on pretty much all the main operating systems out there.

SSHFS is limited to remote mounting, available only on systems that have FUSE available - it doesn't serve the same purpose. scp isn't really complicated, it has similar syntax to its "predecessor" rcp. If all you need is to copy one or two files, scp is just fine. You might also be interested in sftp.

I wondered the same. I've spent a lot of time trying and tuning different access methods to remote webspace. I've tried NFS (frequent lockups, poor performance), Samba (very good, especially with SMB 2.0), OpenAFS (despite local caching, it wasn't really quick).

Then a colleage mentioned SSHFS. I've mapped the webspace and have never looked back. My large web project is indexed by the IDE twice as fast as even the most highly tuned Samba mount I could manage.

In short, SSHFS is an underdog.