A:AnswerWell if you have both sets you can easily try both see what you like better. Having had both the sets the svs for atmos or rear surround is a overall better speaker then the Polk in every way.
Personally I would use them as a rear surround as they sou d cleaner and atmos is not really in every format. Also depending on the receiver you have look in to aura 3d.
A:AnswerThese sound great in any configuration I have 4 sets of these for my height speakers 5.2.8 and they are beautiful for atmos also look into aura 3d similar to atmos but works with every movie I have played so far.