More I hear stories of AA redemption. More I feel the itch to switch over to AA.
Regarding your question. NO F is F. BUT that being said. I can only pin "space" as the biggest advantage on 777 F compared to A380 J. You do have many other advantages but those aren't too big for me to mention here.
So Yes, if space isn't a big deal I don't think you will miss too much and A380 J should suffix.
Jezz. I donno man. It's a tough call. LOL. cuz F is still F.