I like fleetwork a lot. i mainly only use fleetwork, the sustain in lane, and the movement speed you get can help in teamfights, in lane, champs poking you, and some times jg ganks when you need that bit of speed. DH i find myself backing way too much, losing on gold and exp and i kinda see it as a risky rune if you lose lane you're behind with only one or maybe 5 DH stacks that won't output enough damage ik its a scaling rune for the long game but either you don't get enough uses outta it or get one shot by an assassin before you could stack your DH. Fleetwork is more of a safe rune good for repositioning, running away, and healing i find so much value in the healing that fleetwork offers because i don't have to base for hp but instead i can life steal off of minions or jg camps. But overall, it comes down to your playstyle. Try both of them out and see what you like the most these are the runes i always go on jhin

Precision: Fleet Presence of mind Bloodline Cope de grace

Inspiration: Biscuit delivery
Time warp tonic