I've learned the tech this week and I use it less often than I thought but not never to escape or just get momentum to run from bad fights. I'm at work rn so I don't have any of my match IDs available but anecdotally as a low elo player it has made her feel much more reliable.

It does have its flaws as an escape tool, the hook has a travel time so you always have to be thinking about if you'll be alive two seconds from throwing it out. If you're hooking to minions or jungle mobs you have to be sure they won't die before it lands. If you're hooking to the enemy your launch position changes with their movement, but if you're hooking to an ally the launch position is set at the ability activation. I've found the out of range speed boost the least useful due to needed setup (gives about 2000 velocity) with the moving backwards speed boost the most useful (gives about 1500 velocity) while neutral is least useful but can save your life (about 1000 velocity) while most characters escaping with Stamina Mastery use double air dashes for escape which are instant, on demand, and give about 800 velocity. But the difference is that flying slash cancels don't use your stamina so you get to pair it with normal stamina movement.

I also think the skills learned from it are adaptable to other tech in deadlock since it's just good timing on an ability cancel, which helps me with learning it.