User blog comment:AYET/Post-TS SHP member vs old pre-TS foe (Part 1)/@comment-4899461-20120716231327

Well, the interesting thing about Brook vs the other Straw Hats, is that I don't think he learned as much as the other members over the skip. What Brook gained over the skip was the ability to move his soul around freely, and into his sword too. He also gained more musical skill as well. Both are very cool abilities, and it's totally helpful for the crew, but they are just about all he got over the timeskip. I don't think his swordsmanship improved that much, if at all, based on what we've seen so far. That's not to say Brook is a bad swordsman. It's just that he was already quite a good swordsman before the timeskip. How he lost to Ryunma was a lack of pure strength, not a lack of skill. Besides Ryunma and Kinemon's torso, we have never actually seen Brook face another swordsman. His role in fights has been more similar to Robin's, taking out large numbers of lackeys rather than always getting his own person to fight alone.

All these things just make it very hard to truly gauge Brook's strength when compared to other more prominent SHs like the monster trio. And as far as Zoro vs Ryunma, Zoro was forced to fight with his two sword style (even though he did the finishing blow with 1 sword) it makes even the pre-skip comparison shadier too. So I can't really say why I believe this, but I think a post-skip Brook could beat a pre-skip Ryunma.