Not sure what you mean by 'balletic'.
Since the word obviously means different things to different people, maybe it's not really that useful for describing skaters or skating, at least not without further qualification.
Ballet dancers can do both slow and fast movements to the music. Speed is not of the essence, I presume it is in Figure Skating although it does not show prominently in the PCS categories.
Speed across the ice (miles per hour, or feet per second) would primarily be considered under the Power/energy and acceleration criterion of the Skating Skills component.
It's also considered in the grades of execution for all elements that move across the ice (jump entries and exits, step sequences, lifts, etc.) A step sequence could be given -1 GOE just because it lacks power/acceleration and is slow across the ice, and maintaining speed or accelerating can help it earn +1 or +2.
In general, the greater the average speed in this sense throughout the program, the better.
It sounds like you may be referring more to quick vs. slow/sustained rhythm of body movements, strokes/steps, etc. That's kind of quickness is not necessarily preferred per se. But matching the movements to the music is valued, so if the music is quick then quick movements in time with the quick music would be rewarded, and inability to do the steps etc. as quickly as intended would be penalized . . . especially in compulsory dances where such inability could mean failure to execute the right steps on the right beats.
"Variety and contrast" is a criterion under Performance/Execution, so that would reward a skater who shows both quick and sustained movements during the program.
Quick changes of direction are a feature for step sequences.
Also, all else being equal, a spin with fast rotation would generally be preferred over a slow one.
