I am in the same position and I am heavily inclined toward Zensor 3 for fronts. Even if the AVR sets the cut off frequency at 80Hz there is more to a speaker's performance than just frequency response, with Zensor 3 there should be more body and presence to the output. I have been using the Zensor 1s as fronts for a while now but advised my brother to use the Z3s as fronts, I have experienced first hand the benefits of them. They do make quite a difference in my opinion.
I will be picking up the 3s this week. looking forward to it.