AEM Cold air intakes are also one size the whole way through. I think the injens actually change the size of the tube near the filter and make it a slight bit bigger afrer that.

That's limiting the air flow. AEM is #1 for performace and probably the most expensive one too. Their tube is the same size at the begining, middle and end... all the way through. The more even the diameter is throughout the whole tube the more performace gains you will see. I'd say save up and wait a little while longer till you can afford the AEM version. It's the best hands down.