I know that seeing this is a very much talked about/obsessed over topic, My opinions will most likely be out-ruled within less than a few hours.

As acceptable the story of the first story arc was, I'd have to say most other parts of it were. . . Well, If you have a dirty mind, just go grab a milkshake mixer and put chocolate and vanilla in it.

"Most Other Parts" See, As little "Main Plot" there is, It's mostly just scrambled around and detached. Kinda like a bunch of really small legos.
Except, If you can get past the randomness and absence of Important characters, There are some detached stories that really shine out throughout the entire series.
In my case, The particular one in mind is Phantom Bullet, or the Gun Gale Online story arc.

For once, Although I don't like writing, I feel slightly better getting this off my shoulders, Because the author has. . . Particularly bad decision making for properly making a storyline that makes sense. Though I have to admit, although the Alfheim arc was completely NYeaeaeh, It made better sense than some of the things I've seen in these badly lived 13 years.