SRI or CAI, neither of them gain anything higefor power. I have had the ebay SRI for 3 years. I noticed a little power gain, but very small. Makes a cool sound though!
No SRI will hurt power, unless it it is hooked up wrong. the other thing it might be is the filter is a cheapo junk one, which case it might not be letting enough air in. I have had a K&N in every car I have ever had, including my ebay SRI. Might want to use one of them instead of the crappy ebay ones with metal on the filter that can rust.