Read it within 4 days, and I must say it was better than my first impression when I started reading it, but not that good overall, still...
It's basically heavily separated into 5 major arcs:
1) Gag introduction arc - easily the most terrible arc of this manga... yes, it achieved the goal of introducing the main cast rather good... but all those cliche that were stuck from the gag part till the end without any character development to get over those were really frustrating..
2) Xanxus arc - short, sharp, precise. Great arc overall without overly extending it.
3) Future arc - overly long arc with barely anything happening/revealed towards main plot aside of a few extra characters who only matter slightly in the long run... it really felt like a filler that took like 150+ chapters total... the only thing worth mentioning was the actual reveal of the ramen guy who was behind everything in the end and made you wonder for the remaining arcs until the very end when you came to realisation that this must be it.
4) Inheritance arc - well.. it wasn't as bad as future arc, but it was quite meh overall, at least it was rather short, so it didn't make you feel too bored.
5) Finale - well, I must admit even though last arc was rather predictable if you read in the span of a few days, I bet it must have been quite okay if you read it week by week when it was released. It was still a good arc. I don't exactly see why the people are disappointed in ending - I must say that the ending was the most okay'ish part in the arc, but it certainly should have ended by chapter 406 or so instead of 409. The 407-409 is a return of the most terrible part of the manga - gag part. And it's still as terrible as it was at the beginning of the manga.
Overall - it's a shounen with a reaaaaally terrible start(so terrible that I don't realise how it didn't get axed before the xanxus arc arrived) with a slightly above average 'nakama shounen' when it starts running the main plot. Author made too many things explained by 'illusions' for my taste, despite enjoying such approach overall - I think it was too overused as most opponents who ever gave any trouble used illusions in one way or another and the rest felt more of a filler material.
Was thinking of giving it 6/10, but that gag comeback in the end made it drop to 5/10 for me, but it's really close to a 6 though if you don't count the fact the characters pretty much didn't change across the whole journey outside of getting more deus ex machina powerups and if you close your eyes on the gag part of the series or(GASP) enjoy it.