The basic design is pretty much all the same.
The only minor difference I have seen is the distance between the 90* bend into the fender and where the MAF is mounted. The longer the distance there the smoother the airflow into the MAF which gives it a more accurate reading.
For the most part yes they are the same, but there are two different kinds. Fenderwell and non-fenderwell. The non-fenderwell basically just removes all the dust covers from the filter in your engine bay and this hurt performance by actually sucking the hot air from your engine bay, so it's basically an oxy-moron. It should really be called a Hot-air induction kit. And a fenderwell kit takes air from inside your fenderwell. This benefits you by sucking in more dense, cooler air. And we all know when air is more dense there are more ppm in a given area, and therefore when it heats back up and explodes you have more oxygen in your cylinder to help fuel your fires and your result is more horsepower.