At least you're biamping and not biwiring, eh?
Right; I do think there is a difference between the two. I should've made that clear, since I believe this thread is about bi-wiring. My bad.
You have the same listening distance but I have 1/2 the cu ft to fill.
What do you think this will mean in overall value or sound quality at lower volumes, say 90-95 db?
Honestly, I don't think it will make a difference, depending on the amp(s) you have. If your amp is decent in terms of power, you may not gain much if any.
As for value, I also don't think it's worth; I did it because I already had the amps for HT purpose and for a while a tried the bi-amping just to see if makes a difference.
For an almost guaranteed improvement you'll have to go with active bi-amping (bypass the speaker's crossover).
As this is (as you can see) a subjective matter, the best would be to try it for yourself if you can. Only then you can decide if there is difference, and if it is... if it's worth the money (remember the cables in the calculations).