Hi. Currently I have a 7.1.4 setup (equipment on my signature) using an M80v3 as Front speakers. I have the opportunity to buy 3 month old M100 from someone locally in my town but I want check first if I will really hear a big difference on my setup. Room is around 15x19 and normally use for movies and gaming.

M80
VP160
HSU STF2 Sub
4x M3 In-Ceiling
QS10H Side Surr.
QS8 Back Surr.
3x Monoblock Amps, DEN-X4300