This is not the answer you are wanting, but thought to share my experiences.
I've had both the X52 and x52 Pro, and I will not buy a Saitek again.
The x55 is/was made by Mad Catz, and the rights bought out by Saitek.
Mad Catz is superior (in the reviews I've read) to the Saitek x52/x52 pro designs in both ergonomics and reliability. YMMV.
Since I bought a Logitech G940 five or so years ago, my flight simming has been more enjoyable. No issues to date.