Honestly, I don't know much about the turret-type kingpins like the Sidewinder or the Reese 5th Airborne with Sidewinder.  But I did a little research and made a couple of phone calls. 

The Sidewinder is not an extremely prevalent product, but it seems to be on the increase and there are certainly a lot of folks with short bed trucks that like it a lot.  I just don't know if there is enough historical data out there to see how it performs over a long period of time and what effect, if any, there may be on the kingpin or the frame after several years.

I have seen some Forum posts where people claim manufacturers have told them a Sidewinder installed after-market may void a warranty.  Don't know how true that is.  It does seem that manufacturers may be adding extra reinforcement at the factory if they are installing a Sidewinder at that point.

It's certainly not a bad product, and, in fact, I would have to consider it strongly if I were to tow a lighter weight fiver with a short bed.  Reese is a great company, and I would imagine they have tested it thoroughly.  But, at least for now, I'd want it factory installed.

One thing I noticed in viewing a few videos is, although it allows for very tight turns, the tires, wheels, and suspension come under extra stress in those turns.  Because it shifts the pivot point to the kingpin area under the bedroom rather than over the hitch in the truck, tighter turns are possible without worrying about the fith wheel hitting the truck.  However, really tight turns cause the wheels on the "inside" of the turn to pivot rather than roll.  The suspensions are made to do that to some degree, but it looks like the stress is compounded with the Sidewinder simply because you can make those tighter turns.

Slider hitches, where the hitch in the truck moves back to provide a different pivot point, have been doing the job for years.  Most require you to manually engage the slider, which, if forgotten, can cause damage to the truck cab.  Granted, the times most people need to engage the slider are few, but it only takes one forgotten time to cause heartache.

However, the PullRite SuperGlide is an automatic slider hitch that engages while you are driving automatically.  There are other automatics recently on the market, but the SuperGlide is a proven, well built model.   Of course, it's a bit pricey.

Based on my limited knowledge, I would probably look hardest at the PullRite SuperGlide.  But, if the cost was an issue, then I'd do some more in-depth research on the Reese 5th Airborne Sidewinder.

Just my two cents.