Typically, you don't gauge gyro performance by how much or little gain is used. It can vary vastly through models... even on the same type of model as I'm to believe.
90 degrees on the servo and the bell crank sets the appropriate or "close enough" pitch on the tail blades assuming "normal" head speeds and blades are used. Also appropriate servo throw.
I must have made a mistake when JB welding my rod ends as both of my pitch links are bottomed out and I still don't have 90 degrees. I'm assuming I put an air gap in one or both ends and made it too long overall. I've been running it for 50 flights and haven't experienced any issues. I just keep my AVCS engaged, haha. Eventually, I will replace the rod and ends but not worrisome at the moment.