i wouldnt go with bmc as the 2.2 flow is wrong...
the dbilas is good but not worth £270
i have a dbilas intake on my standard air box thats been de-restricted and has a k n n panel filter init, i have noticed a lill diff with this setup does go well.. and will be better when i get the vectra c tb pipe.
all the dbilas is, is a box with a panel filter init