I’m no expert when it comes to digital servos. I’ve flown for more than 20 years & have never used one. I believe they are faster, stronger and more precise. They convert the PWM signal from the Rx to a number and hold that position until the next signal comes through. An analog servo uses a pot to interpret the signal.
Professional pilots can make use of the benefit from a digital servo but for merely mortal pilots like myself, analog is good enough.
Digital servos also use much more current. I've only ever used one, on my rock bouncer steering after killing 2 (still quite expensive) analog ones. It's holding up so far, but unless you're doing really high end 3D flying requiring absolute precision I doubt you'd see a benefit.
I have a problem with digital servos. I bought the f pack from flite test and one of the servos died. I bought 4 (JR DS285) off ebay, when they arrived i plugged them in to my FS-IA6B just to make sure they worked and were centered. All 4 work fine and center fine but at idle they make a noise. like the motor is getting a weak signal. not enough to move it but you can hear it. it seems like it is trying to find center. they are not bound because i don't have them hooked to anything . just sitting on the desk. so can i not use digital servos with flysky ? or is there a way to stop it ? thanks