AFE intakes have been losing power since back in the day of owning an early e60 on a variety of I6 and V8 engines. I realized they simply lose the customers who realize the inherent heat soak issue with an open filter and get newly minted newbies to keep buying them.
Seat of the pants is useless. Many felt the same way back in the e60 crowd to all find out it lost power.
Save your cash, put in a BMC filter and definitely call it a day