P.S: I don't see a backup strategy in your workflow...
I use a Vantec NexStar USB 3.0 cloning and docking station. In normal use it docks a 2TB HDD and is connected to my desktop PC via a USB cable. PS and LR are on my internal drive and external HDD access speed is adequate for what I do. After a big project and at least once a week I disconnect the docking station from the PC (necessary for the standalone cloning feature to work), plug in a second 2TB drive, and punch the switch to start cloning. It takes a couple hours so I do it overnight. Not the best backup strategy because it's not automatic, but it allows me to take my files with me when I travel with a laptop.
The reason I went this route is that the cloning feature also allows me to keep a clone of my internal drive which has my OS (Win 7) and programs. I only clone this when I add or update software. This way if my desktop ever has a hard disk crash, I can literally be back up and running in less than a minute - the time it takes to replace either my internal or external drive with its clone.
A better backup strategy would probably be to keep the second external drive always docked and, instead of periodically using it to clone my other drive, use some backup software to do automatic backups on it in almost realtime , but I haven't taken the time to set that up yet.