Herron VTPH-2 vs. PASS XP-15

Has anyone compared the two phono preamp?

Looking to purchase a phono preamp to compliment my Clearaudio Stradivari cartridge, Graham 2.2 tone arm and Basis turntable. Tube Preamp (First Sound) and Power Amp (Mastersound) are clean and crisp, NOT lush or warm. Cables are all silver.

Any input and guidance will be appreciated.
I've heard the XP-15 once in an all Pass system at a dealer with Magico Mini 2 speakers. It sounded superb, but I don't know exactly what the XP-15 contributed to the overall sound. The end result was very very good so I assume the analoge front end was also excellent.