Having Q750s all around would work great. I don't know if the extra $250 factored in speaker stands for the Q150s as part of the evaluation. Surround Speaker placement is a compromise in distance from any adjacent wall to distance from the prime listening area. For Bookshelves, or Floor Standing, it's about the same impact.\n\nThe amount of sound coming the surrounds will be relatively the same with either speaker, but the Q750s will do a better job of it. Most let the AVR determine the crossover points, and initially you should try the same. You'll have lots of time to tweak everything to your liking.\n\n\nThanks Jim! I initially did forget to take the stand cost into account before I posted, but yes it's $250 extra post-consideration of the stands. Can you explain how much more noticeable the difference will be, especially given the sub will handle most of the low frequencies? Is the difference attributable more to the 'timbre matching' or is it more so the larger dynamics (even though I thought the Q150s can handle the same 80Hz+ frequency range as the Q750s) and\/or wider soundstage\/presence? Would be interesting to hear your insight into this based on your decades of experience!