well, i bought one of those chips, but from a different ebayer. anyways, i noticed a quicker response, and more torque as it states. Not sure if the HP claims are correct, maybe 5-10 at the most.
The reason why I'm sayin this, is after i installed the performance chip and test drove it. I reinstalled the stock chip and felt the difference. The only real way to find out how effective the perf. chip is, is to mount your baby on the Dyno Machine.
anyways i got a lil more juice out of my car from the chip for only $25.00.