The 1/2 ton truck will pull the ATC Toyhauler just fine if you stay close to home.
The Toyhauler by definition will be difficult to tow correctly. Towing rules say that the TW (Tongue Weight) should be 10-20%. This is hard to achieve for any one designing a Toyhauler, with or without toys, with tanks full or empty. For this reason it is very common to use a Weight Distribution Hitch (WDH) to compensate for a heavy Tongue Weight (TW) and most will control trailer sway as a bonus. When towing any enclosed trailer, one can feel like a big kite on a windy day. Also, when passing semis, the trailer has a tendency to get sucked closer to the semi this is referred to as “trailer suck”. ATC owners are lucky because ATC has more room between the axles (spread axles) than most trailer manufacturers and it makes a huge difference when towing in a straight line. I brought home my 2018 28’ FB (Front Bedroom) with my 2017 F150 with 3.5 EcoBoost and Max Tow package (>11,500#; this was the highest rated towing ½ ton 4×4 truck on paper) and a Blue Ox WDH. The ride home was not pleasant even though the engine had plenty of power on mostly level ground. The hitch was not set up correctly so I kept both hands tight on the wheel and turned my knuckles white! Over the next few months I made several adjustments with the trailer empty (except for water) to get the TW at 13%. I put better shocks on the rear of the truck to compensate for the “bounce” (you will know it when you get it). I got the TW, hitch height and the weight distribution bars correctly tensioned, but I still had a little wiggle, and sometimes a bigger wiggle. Even with good conditions (sunny day, no traffic, no wind, no hills, no animals in the road and not 8 hrs into the road trip), this was not acceptable in my mind since the plan was to fulltime in this RV.
Beef up my 1/2 ton truck?
I could have installed E rated tires, and airbags which would have helped with night driving. Even with a perfectly set up WDH, the headlights will naturally be aimed a little higher and one can expect to get “brighted” by oncoming drivers. I firmly believe the addition of a Pro Pride or Hensley hitch (same phenomenal concept by two different companies) would have fixed all towing issues. The Ford ½ ton truck had a payload of 2367#, which is very good for a ½ ton truck! Empty TW of my 2018 ATC FB came in at 1050#, WDH at 100#, topper, mudflaps, floor mats add 400#, 36 gallon tank of fuel add 275#, two people add 300# (good thing my wife is thin!), a cat (cat litter & canned food is heavy!) add 60#. This left me with 202# of payload capacity. If you are thinking about 30# tanks click here. Then I start wondering how much a good rain or mud would add to my weight. My wife had not even started stuffing the huge space under the bed in the bedroom! How many tools would I feel was required to put in the truck for breakdowns?
So I did the math, E rated tires cost $1000, airbags $400 and the ProPride hitch $3000. This totals $4400 worth of upgrades to make this truck safe with an empty truck bed. This situation might look a little different for your use. I do not have toys so I added extra 100 gallon tank or 800# to offset some tongue weight. When you boondock long enough to empty the fresh water tank this will fill the gray and black tanks adding a lot of weight to the tongue! Now I am not the weight police. I do think it is important to be close to the published capability of the truck. I have heard that the insurance company can leave you hanging if you get into an accident and it is determined that the truck was overloaded. This 1/2 ton truck was not going to pull my ATC Toyhauler trailer!
3500 SRW Diesel 
The search starts with finding what $4400 plus my truck could purchase. Many hours of research, many hours emailing dealers and surfed the truck websites. I chose a 2012 Chevy Duramax diesel 3500 with airbags. What a difference! It is a much faster process hooking up the trailer without the WDH. No more planning when I am going to stop or start accelerating before I get to a hill. I just set the cruise and it will go up or down most mountains at the set speed. When I travel the mountain passes the speed has only changed by a few mph. I have since sold the Blue Ox WDH it was getting dusty in the front cabinet and we can always use more space. It would make a difference when it’s windy but it is not a big difference.
Takeaway
If you already have a ½ ton truck and you think you might be happy towing with it, then give it a try. You have nothing to lose and worst case scenario, you can always get a bigger truck. For those of you that do not have a truck yet, I can’t think of a single reason not to purchase a ¾ ton or bigger. The ¾ ton will have E rated tires, better brakes, a stiffer frame, more payload and therefore some many not feel the need for a WDH. The stock Brake controller will be better than any aftermarket one you can find as well. You didn’t buy the cheapest trailer, so don’t cut corners on your truck! For more information on ATC Toyhaulers here is a very helpful Facebook group.
Are you thinking of buying an ATC Toyhauler?
I do install solar and batteries along with some ATC warranty service. Hire the BoonDoctor