i bought the v2 and im happy with it. to be fair though i have only had experience with stock air box and my other intake 4 winter the dc sports short ram. the v2 made a noticeable difference throughout the rpms. and its not just a tube its composed of 2 different diameters of pipe 4 velocity purposes hence the v. i have never experimented with other cai's homemade or big name. not many seem to be willing to fork over the money aem wants 4 v2 and i think because its new and a bit different that people tend to bash. i will also add that the install had to be improvised and i dont feel its a direct fit 4 96-98 civic like they claim. may fit right 4 99-00 though. if i only had $500 and a stock 2000 civic i would look into purchasing a nice header, that is if i werent planning to swap or add a turbo. oh yeah btw you cannot run bypass with aem v2. aem strongly suggest this is not good idea. so yeah watch out 4 puddles.