I havent used the Long Range America tank per se, but I've had both aux tanks and long range main tanks in a few vehicles now and there's definitely a few pros and cons to each.
Fuel shortages down here make modified fuel tanks almost a necessity for travel, so we usually have a LOT of fuel on board. Which option I decided to install depended on the vehicle, but I've had a few 37 gallon main tanks, and aux tanks ranging from 16 gallons to my current setupof a 37 gallon aux tank. A few friend of mine have even installed both for a crazy 79 gallons of fuel on board.
Pros and cons are pretty obvious, here's my take. Long range tanks are much lighter and much simpler. Weight is centered between the axles, no overhang on the rear, no need for a rear bumper and swingaway, no need for a pump, sending unit or gauge. They will carry less fuel, obviously. That's pretty much it. An aux tank setup will carry at least 40% more fuel, but at the cost of much more weight and complexity.
Now these tanks are usually super well made and will last the life of the vehicle, the electrical systems and fuel lines have to be carefully made to match the quality but that's a matter of finding the right technician.
I personally think that when you're used to having longer range, you always appreciate it. Maybe you don't have a true necessity for it, this is especially true for the states where fuel availability is ubiquitous, but you will reduce fuel stops and won't have to carry a few jerry cans around of fill them up if you ever need them. They're alsogreat if you live in a hurricane zone or something similar where you can have a couple of events where fuel will be scarce for a short period of time.
The decision between the two will obviously boil down to really how much range you need. I believe you don't need much in the States. And I would advise to try and keep the tank as small as possible in order to have the lightest vehicle possible. I personally carry 58 gallons of fuel in my vehicle, for about 1000 miles of range. If things were different, I'd ditch the aux tank and rear bumper and install a 37 gallon main tank and be much lighter, but for now I have to carry the extra weight like it or not.
I hope this helps