Well, it’s tricky. The live 10% movement speed buff gives her 32.5 movement speed on worked ground without boots. That’s enough to make her faster than any other champion in the game. However, off worked ground, she has only 325 movement speed. That’s among the least in the game.
Having a low movement speed but being a kiting mage effectively required the worked-ground buff: she can’t kite if she can’t run. Buffing her base movement speed to 340 would enable her to run from many more champions than you might expect by just comparing speeds. It works out to about 80% of League’s roster.
However, her peak performance would be down, since her Rank 5 Threaded Volley has a 3 second cooldown, which, at 20% cooldown reduction, is so short that a fresh Volley becomes ready just after the last one ends. That means 100% uptime, for a constant 32.5-36.5 movement speed buff.
Then there’s the feel of it. There’s nothing else like that in the game. When you push Q and start the Volley, you feel like you’re flying. That’s not to mention the pulse-pounding experience of firing one volley after another, riding the buff, as an enemy bears down on you.
However, there is a related buff to her passive, Rock Surfing. Its out of combat lockout is reduced to 2 seconds, and it grants 40% bonus movement speed right away rather than scaling from 20-40% with her level. That lockout is so short that she could actually use it during a skirmish, and having the full bonus at level 1 means more movement speed all game long. This helps roaming, escaping, and chasing enemies down on a surfboard rather than by spamming Volley.
This buff is more important than you might think. Her rank 5 Volley costs 100 mana. It’s not cheap enough to use as a speed boost. Having a free semi-combat haste would be a good substitute. I dunno. I worry this is an accidental nerf or a nerf in disguise, since the flat 10% buff might just be more consistently useful than a more-available and better conditional haste and higher base speed.