One of my close friends and neighbors has an original, USA made, Traeger Texas and I still use it from time to time for overflow cooking capacity, as I do a lot of large volume cooks. The original US made Traegers were powder coated (at least the one we use) and the metal was significantly higher gauge than the current Chinese-made models, which are very similar IMO to the Green Mountain grills. I can, and still do, cook very decent fare on the Traeger, but the additional $$ spent on the Yoder YS640 was a no-brainer for me and I have been thoroughly impressed and happy with the purchase every time I have used it over the past 2 years.
I realize these are big ticket items and not easy to decide when you can't do a test drive on each one before buying. One way to objectify the decision a bit is to figure out what you're actually buying. A metal box or tube on wheels with a pellet hopper, auger, electronics & temp control, chimney/exhaust, support/chassis/wheels, shelves, potential accessories, but also critically, after-sale support. Ideally, you want your investment/purchase to last and work for a long time in the future and you want the company you purchase from to stand behind you. I may have missed a few details in terms of what you're actually buying above, but when you start to compare grill quality and quality of output, product for product, I think you'd be hard pressed to argue that the Yoder's build quality isn't definitively near, or at, the top of the pack. The heavier gauge of the metal used is important not only for durability and wear, but also for temperature stability and pellet consumption on longer cooks. The Yoder is a tank...the Traeger and GMG are not. I have seen, very recently, a number of supposedly new GMG grills at a local dealer that were left outside for a while that are already rusting before they're even sold. And, there's no possible way I could put a Cambro container with 40 lbs of chicken wings on the shelf safely on either of them. They were built to be low cost with some bells and whistles--but not to last for a lifetime. Honestly, after cooking well over 1,000 lbs of meat on the Yoder (and comparing the output side by side w/ the Traeger, Big Green Egg, La Caja China, or UDS's, all of which I also own, and poorly managed stick burners owned by some good friends), the Yoder puts out the most consistently evenly smoked product of all of them, IMHO. My wife agrees. She doesn't love overly smoky tasting BBQ or meat and she consistently loves everything that comes off my YS640. Critically for me, as the owner/operator, when I have an issue, I want the company that made it to be there for me. I think you can see here on this forum, but let me be first to say too, that Yoder has been outstanding in supporting my purchase, and by reading through some of the threads on this forum, you'll see that there's a constant strive to continue to improve the performance of each model, even after it has been in service for several years. From personal experience, you can't rely on that from some of the competitors...
So, there's no subjectively "right" answer or decision. Objectively, it comes down to overall quality vs. price, and like always (at least usually), you get what you pay for. Doesn't mean the cheaper option is a bad one or that you're making a "bad" choice, it's just a different choice with different consequences. There's a learning curve to every grill/smoker you buy and the Yoders are no different, but nor are the Traeger, GMG, MAK or others...You'll likely figure out how to make the best food you can make on any grill/smoker you buy, and honestly, you'll likely be pleased with it for so long as your grill lasts. So, choose the biggest and highest quality one your budget allows. While you don't do large cooks on it now, trust me, in time, you most likely will!
P.s. I am not a paid spokesmodel for Yoder, just a really happy owner!