What's up guys,
I installed a black secondary spring on my P700 the other day. I raced my friend that has a stock one and it's true that you loose some top speed. We raced from a stand still and I would crank a wheelie with 27" Outlaws (he has the same tires) and he wouldn't wheelie at all. My bike would be about 1/2 length ahead until my front wheels hit the ground and then he will pass me up very slowly from 45 on up.
I definately have more low end pull that I had.
Later

 

Im not sure about the black spring using stock 25" tires but since you are running 27" Outlaws then the black spring should work great for you. Im going to take my black spring out when I install my P700 belt.