Saw a Tweet about this agency so I checked out the website. Never heard of the agents and their bios don't offer anything in the way of their experience, etc. Here's a snip from their ABOUT page:
Are you tired of impersonal rejection letters from agencies and publishers?
Are you frustrated that others do not fully grasp the intricacies of your creative endeavor?
We feel your pain. Why? Because we have experienced it.
STA Literary Agency will read every query that comes to us. We will respond with personal messages and suggestions. We will be honest and tell you whether we loved your book or hated it.
You will not receive this: "I'm afraid this doesn't seem like the right project for me, but I'm sure other agents will feel differently. Best of luck placing your work."
Or this: "You deserve an enthusiastic agent who can champion your work. Of course this is only one response, and tastes vary widely among agents. I wish you the best of luck finding the right home for your work."
This is our promise to you.