Replaceing the stock servowith a digital wont change anything as unless your gyro can "talk" to it in digital. It will act exactly like your old analog.
So unless your updating to a digital speaking gyro such as a futaba 401 or Logitec or similar your pretty much buying (digital servo) a chrome aircleaner for a electric motor.
Actually until your upgrad the gyro you might just go with a faster stronger servo that is more precise such as a futaba 3114 which may be small but is super fast very strong and only 15$ or a sg90 (think low $$ and bang for buck 4-9$)
Are you running a HH gyro now?? I should have asked this first anyway..
Watch for the flak on this post...hahaha