For sshfs if you want to have good performance you need to disable compression. If you think the crypto has to much overhead then change the encryption method to RC4.
Very likely you were running something like 3DES that has very high overhead. And like I said you need to have a relatively recent version of OpenSSH (say a version from the past 2 years or so) for reliable service.
You can set these on a per server basis in your ~/.ssh/config
I have had no problem personally beating NFS when it comes to my personal usage at home over wireless and gigabit link.. although of course this sort of thing is not suitable for large numbers of users.