I've only seen the anime, so I might be referring to something else entirely (but from the glimpses I got, I do not think it deviates much from the manga other than being maybe a wee bit more compact in some places).
Originally, I wanted to rant about how unbelievably annoying, shallow, dumb and whatnot Bakuman is, but Textualpoacher already mentioned most of it, I guess.
Let me add - this work is so full of sports/battle shounen manga (basically the same thing) stereotypes that you could say it actually is one. All the crap that manga kiddies must love so much ...
suberbestest rivalfriends;
excessive use of superlatives (like, how almost each new approach of the MC must and, for sure, will absolutely with no doubt beat their eternal super-suberbestest rivalfriend Eichi ... and then won't);
beating enemies and recruiting them as future superbestest rivalfriends (like the tea-sipping manga girl that - for no apparent reason - looses the bit of (arrogant) personality she has in the beginning and turns into ... nothing; or like that guy doing manga with a think tank of dunno-how-much-people)
humongous amount of (mainly, but not exclusively, male) shallow pride oozing out of every pore ...
it's all there! Yayyyyyy!
I'm not sure if this is anime-exclusive thing or if it's the manga as well, but ... At some point, ALL characters develop the habit of saying certain things - perhaps meant to be slightly more meaningful, deeper, funnier, whatever than the rest - with one eye closed. Really, ALL OF THEM. A-N-N-O-Y-I-N-G. I am as peace-loving and inoffensive as one can be, but I really wanted to smack that stupid look out of their faces, hard.
What's else to say? Oh, in all fairness, the work has its good points as well: Hiamaru and his editor are funny, Kaya (Kaya? ... the girl with big tits) is kind of likeable (although a bit generic).