Filtration will be the benefit of the K&N one. In general, a lot of pods don't filter as well as the oem filters, thus allowing for more dirt and dust to enter into the engine. For example, the Blitz and HKS pods don't filter much at all. K&N has one of the best filters out there, although you should try a dry based one, such as apexi, as they are a lot easier to clean, and no need to coat the filter wth some oil thing, in the case of the K&N. cais and sris generally give more power due to them sucking in more air. With sri's, most of the time you will be sucking in hot air from the engine unless it is completely sealed and has a cold air feed to it. Cais get there power from sucking in colder air, thus allowing more air to reach the engine. I hope I explained it right..... If I'm wrong someone please correct me on this. On your note about the price, I guess your paying for a filter that not only filters better than the generic one, but also the warranty....