we;; they thought that initially (the 20-30hp) but they've been debating that. If you look they've updated their page..
there is power to be made no doubt.. I have the DP, it rocks.. Buy it.
The car is definately effected by heatsoak after a couple runs, so a new IC will show gains. You won't gain any *more* or peak hp, but it will stop you from losing power when it heats up.
The biggest issue with these cars is 1) the ECU - very conservative on timing, and very rich. Also very aggresive in pulling timing due to knock, intake temps etc... 2) fuel. It's starting to look like the MSM doesn't have any larger injectors than a non-turbo miata