At first it would seem like your average shonen, but it was actually one of the best IMO and actually what shounen should be like.
Was a pretty interesting way to tell the story - swapping between different characters at approximately same time frame and adding new characters in same style only to see all the small details merge in the end, I must say that it was pretty darn good... I imagine it would have been one hell of a cryptic read if I didn't read it all in 1 day and instead read it volume by volume...
There have been a few fan service annoyances, but those were mostly bearable.
Sad to see it end midway... and apparently even continuing with novel - you still wouldn't reach the end and it seems more of a permanent hiatus now, after all those years.
Well... can't rate this higher than 8, since it's impossible to tell how it would be concluded even remotely. There are still too many questions remaining to give an adequate opinion.