Sail arms are faster. They go through the whole range of motion in under a second. This suits some smaller boats. However if the boat is very small across the beam you will not be able to use a long enough sail arm to operate/control/pull enough length of sheet to do the job.
The longer the sail arm, the more length of sheet you can pull. However, you need to balance the torque (kg/cm) against the cm of the arm.
A sail 'drum winch' can have up to 6 turns (depends on actual model), the speed of turn is a factor, but the torque is less of an issue. Very expensive sail winch drums are fast, cheaper ones are not.
Another consideration. Sail arms are largely tangle proof. Drum winches can cause problems if the line goes slack and hops off the drum. You need to look at a tensioner mechanism.
Continuous loops are another solution, and require a drum winch.
There is no simple answer.
I prefer sail arms, and use 1/4 scale servos where I can. But 1/4 scale servos are large and would not fit well in smaller boats. My preference is based on speed and that they do not tangle. Also 1/4 scale servos are cheap and powerful, but would not fit in my smaller boats.
This is my personal preference.
Many sailors prefer sail drum winches, but the can be much more expensive.
I would tend to go with what is recommended in your plan/kit. If for no other reason, the geometry has been sorted out already.