Haha AB! was a pretty good anime, but I felt like it was too short, according to the company that produced it (I absolutely adore 'Key') they're planning on releasing a visual novel for it sometime this year, but that's probably pretty irrelevant to you guys since you probably don't play/read visual novels, nor fluently understand Japanese. xD

But yeah, Fanboy preaching~ 
I personally liked the other works by the company like; Kanon, Air, Clannad, Little-Busters xD
[s]Even if Little Busters was also rushed, and basically lacked my favorite characters >_< Still hoping for an OVA...[/s]

But yes, as I stated awhile back, seeing AB! won't really make much of a difference, the concept is borrowed, but this roleplay is it's own world. Feel I need to keep saying that since I've had bad experiences in the past where people start nitpicking lore and presenting theories about source material.