That filter should do just fine. Your standard air-box has a cold feed from the offside front of your engine bay and a hot feed through a pipe connected to the exhaust manifold. A mechanical thermostat regulates the hot/cold mixture for best efficiency. You can ensure that more cold, dense air gets into the engine by removing the metallic flexi-hose between the manifold and the air-box. Fuel economy will be reduced by doing this though.
In fact, panel filters in general are better than most of the flea-bay cheap induction kits. The standard air-box takes air from a cold part of the engine bay, and the plastic construction minimises heating of the air, despite its position above the camshaft cover. Many of the cheaper induction kits bolt straight onto the throttle body, with the filter hanging over the hot engine head. This can only provide hot air to the engine, which will DECREASE performance compared to the standard air-box, which at least has a proper cold air feed.
To significantly increase performance, you need to ensure an exclusively cold air feed. If you look at
this by GSR Engineering, you can see that the tubing is shaped such that the filter is located in a cold part of the engine bay. This guarantees better performance. Notice also how the pipe is flared, rather than fixed diameter. This is to reduce turbulence and provide a less restrictive air-flow than poorly designed kits.