OK. My question was too general. To your point above, I've answered all those questions.
Let me be more specific. I hear people beat up on Lang or Bubba and praise Meadow Creek. To me, the untrained welder, the basic difference is one used a matte style paint and doesn't always grind all the welds smooth (Lang and some older Bubbas) while the other uses glossy paint, chrome and smooths the welds (Meadow Creek).
Speaking specifically to the welding, does grinding off the metal/slag provide a more secure or better weld? Are there other quality issues that the average person cannot? Are these actual quality things as opposed to preference or looks things? For instance, I can tell you the difference between using a particular type of RAM in a computer over another. But whether you choose Apple or PC is a personal preference.
Another example, my builder puts square stacks on his smokers. Volume and everything is equal to the round ones (we use the BBQ Builder calulator) but I, and other folks who use him, like the "custom" look of the square stack. If someone tells me that empirically evidence/physics shows the circular stack is better because it draft better due to a lower surface friction and less turbulence, then I will say to him, use a round one on my new build. If people prefer round because it looks better and has no welds, I could care less about that.
In short, are there things that make a reverse flow design better functionally, not cosmetically. Should vents be a certain shape, stacks a particular make up, ends flat vs round, etc. I don't care about shiny paint or chrome.
