By isolating the filter closer to the cold air source you create 2 really important items.

1. You no longer have an isolated area were turbelent air can get super-heated i.e. an airbox on top of the valve cover for the cylinder head.... X-fire's design.

2. by filtering at the source of the cold air, the air travels straighter down the plumbing with velocity, the air will no longer hit an airbox then a funky air collector before getting to the MAF. If the flow of air over the maf is constant and has little turbelence (CAI method) the maf can calculate the air flow better to use in the emissions calculation and air/fuel calc.