I have owned both, and there may be others here that have as well. I can tell you they are both good. I still have the Rec Tec, and do not foresee letting it get away from here. Smoke is a function of burn efficiency. In other words - the lower the temp, the better the smoke out put...to a point of extenguishment of the burn. Smoke output is not the strongest suit for either of these - but think they were adequate in that area. It is cheap to add an Amazen Smoker to any pit and amp up smoke production.
Let's consider the build, and the controllers. That is where the rubber meets the road ( or the meat hits the grate!
)
The Yoder is the heaviest built pellet grill for it's cooking area/capacity. Built by a company that makes the best in offset stick burners in my opinion. Made with 10 gauge steel, and all fabricated in the the USA. There is a "feel good" about it and the company's attention to quality fit and finish.
It is considerably more expensive than the Rec Tec. Do you get more? Well..let's look a little further....
The Rec Tec is not built in the USA. But it is built in a plant that is tightly controlled by Rec Tec. The steel high temp powder coated, and a little thinner than the Yoder. But - I need to point out an un-comfortable fact here: thicker steel
does not hold heat better... Allow me to explain this - steel is a very good conductor of electricity isn't it? And - just like with electricity, it is very thermally conductive. Ever accidentally put your hand on a smoker with the fire going inside it? What happens? the heat energy passes thru the steel like wind thru a screen door. Which happens almost immediately. So - the theory of "thicker steel holds more heat" is a wive's tale. The steel will soak up thermal energy until it begins to pass it thru to the unheated space ( exotherm ). You
pay big to heat up a pit that is built with very thick steel. And - you don't get it back in efficiency - because after you quit cooking the steel continues the exothermic process until it can reach equilibrium with the air temperature outside the cooker.
So thicker is not always better for cooking.
And..it took 5 lbs. of pellets and hour if I wanted to run the Yoder at it's top temperature of 600F as a side note 
The controllers: Rec Tec uses a controller that is made by the company that makes controllers for Louisiana, Memphis, and a couple of others. It works very, very well, keeping temp swings usually to less than 5F.
The Yoder controller is designed by Yoder....I refer to my above statement to remind you that they do in fact make what I feel is the premium quality built offset smokers.....but the controller on the YS640?....
I want to say they are on version 26(?) firmware update....
When you set both grills side by side and compare a few things - you notice that the fire pot on the Yoder is on the left extremity. Like an offset. But, because we use fans, and electronic to control our temps in these units....Why? I think that the design parentage of the venerable offsets influenced this. But it does not help you get even temperatures across the pit. It is not uncommon to experience 50-70F from one side of the pit to the other. Good? Bad? ...You decide. Think about how you cook, and intend to use your pit.
The Yoder uses a stainless fire pot. The Rec Tec does as well, and a 10 ga. stainless heat deflector, and pellet auger, and 10 ga. stainless drip pan. The Rec Tec pan has not warped. That was not the case with the Yoder. The Rec Tec has a 40 lb. pellet hopper. So it can take an entire bag of pellets. The Yoder holds 20.
Rec Tec also has a useful light in the cooking chamber. I thought it was kind of "gimmicky" at first - but I confess - it is darned useful at night.
So - my bottom line opinion came to this:
Dependability, cost, and cost of operation, even grate temps. became more important to me than a heavy pit - that the body may in fact never burn out from your use. But, I don't think the Rec Tec will either. And - it is a good looking pit to boot. Spousal appeal is an important factor
The Yoder
will reach 600F while the Rec Tec only 500F But....a set of grill grates on my Rec Tec, and I can sear steaks at well below 500F. For much lower rule consumption.
The warranties on both are good. The customer service I have received from Rec Tec has been unbelievable. The Rec Tec in my opinion is a better performing, better priced, better looking pit.
And - as a disclaimer:I bought both pits. No gifts. Both companies make good products. I still have the Rec Tec.
