Thanks for the additional information. Your print settings all look correct, except you have an embedded profile of "Phase One Gray G2.2", but I have no experience with this profile and it may be the same as the standard "Gray Gamma 2.2", though it may be worth converting an image to Gray Gamma 2.2 in Photoshop, then making a small test print to see if it differs.
Other than what I think looks like a slight yellow staining in your highlights (or, is it the paper color I'm seeing?), I think your prints look pretty good, and normal for Piezography output.
Compared to Epson ABW, the initial reaction is that Piezography prints look "flat", but this is because Piezography is able to print linear and show extreme shadow and highlight detail (Epson ABW forces untrue contrast to make brighter highlights and darker shadows than is true to the image). Piezography prints true image information, so 10% prints 10% gray, 30, 50, 80, 95, 99, etc... What you want to do now, is make adjustments to your image to get the desired contrast with Piezography. Black will only print where the image information is pure black, so if the image doesn't contain pure black, it won't print black- and can make the output look flat. Please refer to the "NEW Piezography Manual" and "Where is the Black?" documents on our Piezography technical support page, here: http://www.piezography.com/PiezoPress/technical-support/ for information on adjusting image contract, get true black, and how to make a fine Piezography print.
Please let me know if you have further question or there's anything else I can help you with.
Best regards and happy printing~ Dana