It's good but in my humble opinion---not as good as most people thinks it is.
I agree with you, the storyline is good but for me it was easily predictable...I already had a good guess about who the Sunflower Samurai was and i was correct eventually. I like that ogre-looking character tho, Oniwakamaru. Big sniveling abominations just spark my interests for some reasons...It's a pretty good thing that he had more character depth in him, he ain't the generic big sniveling abomination...I guess y'know what i mean if you have already seen him either in the manga or in the anime.
I wanna ramble on with the whole plot but yeah i don't wanna spoil you and this is not the spoiler's section...
What i liked about it? Like a usual Samurai-based show, it embodies Japanese history. It was unique in a way that it pieced traditional and modern stuff together....I mean you just gotta enjoy Mugen's capoeira-ish style. The animation is pretty crisp along with the art, that crispness is pretty normal considering that it spanned only 26 episodes.
Oh, i forgot to mention that it was created by the renowned Shinchiro Watanabe...W/c is a good thing. But i've always had problems with his works....Refer to "Dislikes"
Dislikes? This is completely preference-based. Its creator, Shinichiro Watanabe is the same guy that made Cowboy Bebop...and like Bebop, it didn't do so much of a connection with me. Besides all the good things i've said about it, it's just not a standout IMO. Something's just missin'...Y'know it's like one of those "that was a good show, so now let's get our lunch".
Highly commendable but not memorable.