I don't have a 25FX, but I do have several 32SX's that are a drop-in replacement for a 25FX. I was thinking of using a .15 as a means of keeping the weight down. The retracts I have are only rated up to 48OZ. They are of the air up, spring down type. At least with a .32, it won't be lacking for power. I have an F-82 with a pair of 32SX's that does just fine at 9 1/2 lbs.