RE: Delay/Gain for Hitec HS-625MG
Gain will be enough to hold the tail but not too much so that it wags, start with 50 percent and go from there.
To set delay do a full speed piro and let go hard at the end, tweak the gain up a little at a time until you get a nice stable stop, if it bounces you need more, run just as much as you need.
Start saving for a 9253 or 9254 servo you will notice a big difference.
Also MAKE SURE DS mode is OFF or that servo will last about 1 flight.