I've gone ahead and ordered the Paramount Phantom blades, so I no longer need the information. I'll just compare when they come in since my P99s have only been sharpened once and are practically new still.
I'm a bit puzzled by your selection here. Above you wrote:
(my options are open, but I'd prefer to avoid Matrix due to the sharpening inconvenience).
I skate on Paramounts (12" profile, nominal Gold Seal model, 440C stainless steel). Paramount uses a design similar to Matrix (though different from Matrix in several key details): a plain-carbon-steel or stainless-steel runner attached to a thicker aluminum-alloy chassis. Hence, the Paramount, as well as the Matrix, blades require an appropriate jig (sufficient jaw capacity and range of vertical height adjustment) for sharpening.
Also, although some lower-end Paramounts have runners fabricated from plain-carbon steel, the 17" profile, nominal Phantom model, blades have runners fabricated only in either 420C or 440C stainless steel. Be aware that either of these grades are more difficult to sharpen than plain-carbon steel; the 440C particularly so. I gave feedback to my tech to help improve his sharpening of the 440C.
In summary, for a decent sharpening, you'll need a tech with a proper jig and with experience in sharpening stainless-steel blades.