User blog comment:Bankai99/That's Some Real Devotion/@comment-3075024-20111107033433

'''Its not about how much time you spent with the person, its about what feeling, bonds and trust you made during that time. If Brook and Franky wanted to make such "Ground-less" statement only after spending like 5 days with Luffy then its possible for them cause they both shared a life-or-death battle with Luffy. Franky at Enies Lobby and Brook at Thriller Bark. For them to trust eachother's life in eachother's hands and fighting together is enough reason and bond for them to connect their selves and grow stronger.'''

So yes, what Brook and Franky have for Luffy is real Devotion without a regret.