That’s a very reasonable reasoning.My honest, non-testing experience: the Q50a's are great speakers for surrounds. The R8M's definitely opened up the room a bit but I don't think it's worth the money. Can't comment on the older R8's. However, if you can afford the R8M, you can't go wrong.
Still, I would be curious to see how much worse, or at least different, the Q50a are.