The 8's have a superior midrange over the 7B. As for the rest, I found the 7b on the lean side, particularly for HT. The 8's need 250W or more to be happy. You are a lucky dog to have the SW12 though, and either choice would work. Aerial is also introducing a stand mounted 3-way.
Aerial 8B vs Aerial 7B
I am trying to decide between these, I already have the aerial sw12 sub, my room is average size, using a sunfire theater grand signature amp, would the 8 be overkill on base, looking for opinions from Aerial owners