Yes, the wallet gives you much greater flexibility. I struggle to think of a reason to choose FFC over wallet, other than when one has a reason to keep the booking alive, which are probably fairly limited, e.g. to qualify for a specific promo, or for expense tracking purposes. The only other thing that comes to mind is that if one can subsequently cancel FFC to the wallet, it might be possible to get a longer timeline by leaving the credit as FFC until just before that expires, then convert it to wallet and get an additional year. But I don't know whether that's even possible.

Maybe someone else has thought of another reason why FFC might be better.