The Reese Strait-Line products are great WDH's with integrated sway control...., mine has performed great for 10 years.
Your 2016 X23B has a GVWR of 4,950lbs......, if one loaded the X23B to it's GVWR (worst case) the ideal loaded tongue weight would be 644lbs to 743lbs (13% to 15% of HTT gross weight of 4,950lbs).
IMO if you are going with the Reese Strait-Line WDH (or any other WDH brand), go with the 800lb rated product (not a 600lb). The 800lb product isn't overkill for a 550b loaded tongue weight on the X23B.
Reference X23B thread: http://www.jaycoowners.com/forums/f3...s-20492-2.html
The Equal-i-zer brand WDH is another favorite product with integrated sway control as well.
Like any WDH, proper installation/adjustment is key for optimizing the performance of the WDH.