BokuTomo happily copies some of its parts from other school and harem comedies, but uses them together in a surprisingly effective and relatively original way alongside its own ideas. The eccentric student club is taken from Haruhi among others, Kodaka is like the protagonist of Toradora, Yukimura is an obvious parody of Kinoshita from BakaTest, the girls basically form a Negima!-esque harem, and like Seitokai no Ichizon, it pokes fun at otaku culture.
What it adds to this formula is a more likable protagonist (Kodaka is funny, strong and quirky, rather than being a boring and geeky reader avatar), insane girls who don't quite fit into any stock character, ala Breakfast Club (like an arrogant rich blonde who suffers the jealous resentment of others and loves H-games) and just plain funny situations. My favorites include the girls' failure at playing a dating sim and the collective novel writing.
It's fun. However, just as a warning, you will enjoy this manga more if a) you are familiar with otaku culture, as there are many in-jokes and references Lucky Star style; b) you can tolerate jerks as main characters and realize they are not meant to be agreed with; c) you like, or don't mind, 'weird' (by western standards) and sexual humor.
REPLY TO SPEARSMEN620:
First of all, I wasn't comparing Yozora to Haruhi specifically, but rather the basic 'unusual club' setting. (In fact, I specifically said that the girls weren't stock characters, but rather, deconstructions.) I do think though, that with hindsight, a much better comparison would have been to the clubs in Seitokai no Ichizon or Seitokai Yakuindomo (at least in their anime versions). I also wrote "among others".
Secondly, I stand firmly by my stated impression, when I read BokuTomo, that it inherits some of the specific ideas and conventions of previous work(s) (and yes, you know what, a lot of manga/anime indeed do that) AND cleverly subverts them, AND has ideas of its own. I find it hard to believe that Kodaka's mistaken reputation for delinquency is a 'coincidental' similarity with that of Ryuuji (or that Ryuuji's wasn't itself inspired by the hero of Angel Densetsu...) - likable though he is. Or that the adorable and funny character, Yukimura, would have existed without Hideyoshi from BakaTest (even his haircut is similar, and yes, I'm aware of the spoiler about him). Or that BokuTomo isn't (at least, so far) a harem manga - a very well-established, well-known format.
Perhaps "copies" sounds too pejorative for a manga which I love, eagerly read and recommend; I wouldn't have given it a rating of 8.5 if I didn't, but, well, "It's just coincidences" isn't an accurate analysis of such elements either. And what's the real difference between 'obeying a cliche/convention' and 'copying previous work'?