Propane Tank Issue

I think the Sway Control is varies to power to each wheel to control sway with brakes.

I had the brake controller professionally installed as running the wires on the car would be a total pain without a lift.

I was in the foothills of Penn and VA as I didn't want to take I95 around DC so it was hilly but no wind. The Aeroplus looks interesting.  I don't have racks on my Escape so I guess I'd have to add them as well.

There are certainly conditions that would challenge any rig, but the more marginal the setup the more likely that is to occur. In many cases we can avoid those situations by choosing to wait until conditions improve, but often surprises happen. 

The other consideration with a marginal rig is lack of flexibility in the form or reserve capacity if the mission changes and say one wants to do a little boon docking or carry a couple extra passengers. 

I too have towed for many years and originally thought that I might tow an rPod with a 3500 lb rated vehicle. I would have been overweight. Being a Toyota guy, I was looking at a Rav4 and got the Highlander instead.  Cost is certainly an major consideration for me and most of us on this forum. If it wasn't we would probably be driving around in much more elaborate dedicated RV's. I couldn't handle a $10K cost difference either, so I buy used vehicles so the cost difference is not much. The Highlander gets a couple less highway mpg than the Rav with the same drive train not towing, there's wouldn't be any measurable difference towing because towing fuel consumption is dominated by the trailer air friction.

For sure a wdh will help improve rig stability, including sway stability. When you hang a trailer on the back of a TV it unloads the front axle. That is especially true for a compact vehicle with a short wheelbase.  Resistance to sliding is proportional to weight and the front axle is your steering control and has the best brakes on the rig, so taking load off it reduces its ability to control the rig. The wdh puts the weight back where its supposed to be. The problem with a wdh is that that load redistribution is not constant, it depends on the road being flat. If you say drive over a high spot the wdh loses tension and load shifts back to the rear TV axle from the front. That's why wdh's generally don't increase tow capacity. But they do help ride, handling, and braking.  

I think it can probably do what it needs to with just an accelerometer. Its mounted on the front crossmember so in a sway event it measures lateral acceleration of that point relative to the axle. Displacement in mathematical terms is just the second integral of acceleration, so from the acceleration it can know how far the sensor has been displaced side to side. If it knew how far the unit was from the axle it would be able to easily calculate the yaw angle, but I don't see where it is ever actually programmed for that distance so it probably doesn't know the actual angle,. But it probably doesn't need to, it can learn what is normal yaw while turning and distinguish oscillations in yaw due to sway from that.

 Interesting device, but boy is it pricey.