Actually, I do not have either of those models.
I took advantage of pro-audio's offerings and have a pair of Focal Twin6be's:
I bought mine at $1650 each, but I see they are now getting $2200 each for them. Their success in the recording studio has paid off!
At the time, the pro-audio option was much less expensive than the home audio version (which have avant-garde styling),and having amps specifically chosen for each woofer and tweeter, along with the active crossovers makes them damn near bullet proof. Before the return period ended (I got them from Sweetwater),I cranked them hard and one feel silent, then the other within 3 seconds of the first. I turned them off, turned down the volume and then flipped them on and they just went about their business of making high sound quality!
But, to the OP - you might consider the pro audio offerings, but to answer your question, if you have the money to get the Be tweeter, get it.
That said, I'm sure the Aria (which I have never heard) is a very fine speaker, but recording engineers are in the business of listening critically ... non'stop and the Be option has established itself as something worth having!
Just for the record, DTS Labs uses Focal Twin6Be pro-audio speakers all of the way around for their reference demo room (where they take people to impress them with how good their processing sounds):
I use mine vertically instead of horizontally, but I'm sure DTS gives their guests the sofa in the middle. The chairs at either side of the room are clearly not positioned for fidelity!