In that case, you may wish to consider these Futaba servos compatible with the 'SR' mode on the 7PX. This will marginally improve the response speed of the servo. Brace yourself for the price, but Futaba servos have great resale value and have long been regarded as top-tier, long lasting equipment. https://futabausa.com/product-catego...super-response

Also, in general Futaba's servos seem to be rated quite conservatively/accurately and post videos including some of their tests, including comparisons against their other products:
Because of this I trust Futaba's speed and torque ratings more than a lot of other brands. I think along with 'C ratings' on batteries, servo specs are better used to compare within a product line rather than across all different brands.