Look a few posts up
"Twenty-five degree swings don't matter much at 225°F+ or searing a Steak...BUT...Low and Slow smoke cured Sausage or Fish at 150 to 170° with a 25° swing and you got garbage. So there is a benefit to 5° control. Just up to the individual to decide their needs and budget...JJ"
Yes, but we were talking about pellet grill owners. I greatly respect JJ’s opinions, but as far as I know, he has never owned a pellet grill. As far as slow smoked sausage is concerned, I use a cabinet smoker and would not use a pellet grill. Most do not operate reliably at 150F. As far as temp swings, the most extreme swings are at the higher operating ranges. I’ve low smoked plenty of salmon on my CampChef with great results that are indistinguishable from salmon smoked on my Memphis.
Remember too that grills are not at the extreme end of the swings for long. Home ovens operate similarly. My home oven has 25 degrees of swing, but an oven thermometer, which responds slowly, registers a constant temp.
We also need to clarify some things. First of all, there’s a huge difference between wide swings, and wild or erratic swings. With the former, your grill will operate with consistent, repeatable results. There are some grills (PID or otherwise) that have wider temp swings than others. But the swings are consistent and the temp averages out fine. Other grills have erratic swings. On one cycle, it may overshoot 15 and undershoot 5, the next pass over 25 and under 20, etc. This makes the average temp drift over time and produces inconsistent results. The former is fine, the latter is not.
I had great results with my CampChef which had 20-25 degree swings. So if +/- 25 is good, then people naturally assume that +/- 5 must be better, right? Again I have to ask, what evidence is there that it will produce better results? And in fact, many folks believe it will produce worse results in regards to lower smoke output.
So is any amount of swing too much? I’m sure there’s a practical limit, but in my experience, 20-25F is fine. To me, a more important concern about temperature is variances from left to right, up and down. Many owners report variances of 60 degrees or more. Even though you can learn your grills hot spots, and “use that to your advantage”, I’d rather not bother. If I want multiple cooking zones, I'll buy an FE.
Again, I agree with most of your original recommendations. I’m only arguing the statement “You want something that will maintain temp within a 5 deg swing”. As far as I know, only one manufacturer claims to have temperatures swings of +/- 5 F. My current grill – a Memphis Elite – usually maintains temp within +/- 8F. You’d have a hard time convincing me that another grill is better, just because it can maintain +/- 5 degrees.