One other factor is weight. If you've narrowed down your options for a fifth wheel, then you have to think about carrying capacity of the truck (pin weight of the 5th loaded, passengers, fuel, and "stuff"). Some of the sliders can be very heavy. A Sidewinder combined with a conventional hitch can save a lot of weight.
Many love their B&W hitches, but B&W won't warranty them when used with a sidewinder. I've been pretty happy with my Reese, now called a "Titan" 16K. You can easily separate it into two parts, which makes removal easy for one person.
