cold air or short ram no real difference. with the cold air you run the chance of sucking water. as far as the brand most are the same the filter is the difference oil or dry, the only one that is different is the AEM V2 it has a Helmholtz resonator on it maybe 1 Hp more. as far as power gain maybe 3-5 tops, but you will get better air flow and it will sound better. as far as heat goes the under hood setup is such that a short ram will not be effected by the heat of the engine like in other cars. for quick efficient power i would go with a short ram with the new oil free washable filter.