The only problem with their SSH agent is, if you store let’s say 6 keys and the server is set to accept a maximum of 5 keys before booting you, and the correct key happens to be key number 6, you can end up being IP banned.
This happened to me on my own server :P
That being said, my experience was using the very first GA release of their SSH Agent, so it’s possible the problem has been sorted by now.