When Udyr has no boots and can still outrun a Singed with Boots of Swiftness + ult
Maybe that's a bit of a problem?
Edit: This has happened to me twice now. it's not so much the movement speed as it is the movement speed + stun. I've seen an udyr get up to around 600 movement speed before. Singed can outrun him in a marathon, but in sprints where it matter udyr rips my fucking face off. Most of the time he can even ignore rylais it seems.