I think it's worth a try, at least you'll get better tonal/timbre matching across the fronts which is a good thing. Just that alone will likely provide a better overall experience.
I remember listening to the FRx series before, they were pretty good, but the Athenas will definitely give them a run IMO....whether they are any better is really up to you to compare, I can't remember much about what the FRx sounded like, but they were decent speakers that represent good value.
Best Buy has a return policy, make use of it...just buy them and try them side by side....that will easily answer your queston