You should always
opt for shared key authentication instead of password logins.
There are several malicious scripts out there that will try to brute force guess your SSH password. Those attacks will fail 100% of the time if you disable password logins and only allow shared key authentication.
Now a good thing by using shared keys is that you can have a key for the root account, and when you want to ssh a box while running as your user (you are running as your user aren't you!), then all you would need to do is:
su -c 'ssh box_to_connect_to'
Enter your local root password to be able to use the key, and then you will be logged on to the remote host without the need for a password.