I do not use subs with my setup. I can make my system have too much bass or too little bass by moving the speakers and seating location in the room so subs are not necessary even in my large room. I have heard the 3as with and without subs and they definitely sound better with subs in the system, but I don't believe they are a must have for good sound. I don't think that the difference in wattage of the amps is what makes the speakers sound better because they did not sound good at all even at low volumes with the A23. With the A21 the 3as sound great at all volumes. My wife is not bothered by the look of the speakers, but they are in a dedicated room so aesthetics come second to sound. You can check it out if you click on my system link by my username.
David