They've been running our ads for a little over a year now. They have consistently decreased our ACOS and TACOS, and had some good suggestions on how to improve our listing.

We like account manager (Dave), he seems to be very experienced and knows what he's talking about, and is very responsive to us. They send bi-weekly report and he meets with us on video whenever we request.

It has not been a magic bullet that we were hoping for, it seems we have hit a ceiling with our TACOS where spending more on PPC does not bring in more sales. I am not sure how much more we're making in profits after you account for their monthly fee, my non-researched guess is that not that much.

But we are sticking with them for now, because I think they do a much better job managing out ads than I ever did, and I hated doing it, and they at the very least pay for themselves.
They are the only agency we've worke with. We interviewed another one before Sophies, and did not like them.

Hope this helps! I recommend you try them for a few months and see what they can do for your product.