I have to agree that with the same cook prepping the ribs the same way for all four smokers, that this will come down to the smoker, not the cook.
Since all four smokers use some sort of temp controller, even the temp becomes part of the control.
The variable is the fuel source of each smoker and how the heat and smoke is presented to food.
stick burner, pellet pooper, electric, lump charcoal
I'm pretty sure which ones are going to be first and last, the middle two will be a toss up.
I vote for not wrapping, it can introduce a variable.