With the trade up allowance there is not that big of a difference in what it will cost me for the QS8's over the 4's. However, my listening area is about 8X12 and I a m afraid the 8's might overwhelm the area. I plan on using only a 5.1 system, so that's a consideration. What is your opinion?

Eddie, no speaker can "overwhelm" a room. You're in control of it by calibrating its level to balance the others. Obviously it could be turned practically off and then would certainly be "underwhelming". Nevertheless, the QS4s should be plenty for your room if you decide not to spend more.

Some people have m80 loudspeakers in rooms that size, there really is no overwhelming, unless you have your speakers incorrectly calibrated.

The important thing is that some speakers are not that good at low power (thus forces you to crank up the volume). This is NOT the case at all with ANY of the Axiom speakers I have (80, 150, QS8 and EP500). I listen (when neighboors are in) at low volume and nothing at all gets lost.

The problem usually lies in the thought of the next room you want to put your system into and that room may be much larger and then the QS4s might not be upto the challenge. IF you can afford the QS8s get them, if all you can afford are the 4s buy them, to me it is more a price point for the QS series and the later upgrade in room size than a question of sound quality, both are great in that department.