I'm not Helen, nor do I work with or for her (ie. I don't work or have anything to do with
Adorama 
)
Helen mentioned the 25 free prints and said people use them to print the various different papers. Wish I thought of that when I sent photos for print, I would have done that. I just sent for prints.
What I did do was sent 3 identical images (1 color, 1 B&W, and 1 antiqued processed) to 3 different companies, to
Adorama, to a highly recommended other printer, and to a printer that is more general population oriented.
My results were that I was floored at the
Adorama print quality over the other 2 printers (remember, the one was a very highly recommended and very often recommended printer.) I did have color correction marked at all 3 printers and do not have my monitor hardware calibrated. It is calibrated using a website, the best I could do.
When I put the
Adorama prints next to my monitor, they were spot on. They looked exactly as they did to the screen when I processed them. In comparison, the highly recommended site were great prints but they were oversaturated with the colors and didn't match my screen. The general population printer was the cheapest and it showed in the quality of the prints. You could clearly see areas that were very pixelated and no longer sharp.
I also had some 8x10 photos printed with that batch of free 25 prints at
Adorama and they were stunning as well. Unfortunately, I have a ton of images uploaded to
Adorama, but haven't had the ability to order any prints since then. I was happy enough (I was extremely happy...) that I won't bother with trying any other sites out and plan to stick with
Adorama for future printing.
Again, I have no affiliation with
Adorama, but when I get something I am extremely happy with, I want to express it. And I was extremely happy with the prints from
Adorama.