I'm going to be brutally honest: I have not seen a significant difference when I use windlance, specifically on my core team.
I feel the movement speed (which I personal believe is one of the most important stats in the game) is simply so insignificant the chances that its a waste of early game gold.
Now, I know melee heroes get more milleage out of orb of venom, because the first "tag" reduces the enemies' ms so much that windlace is obsolete and for heroes that really need extra chase, I usually build phase boots.
I am told its useful for slower supports who use brownboots like CM, Lion and wd but I don't play those particular support heroes. I usually play with rhasta, dazzle or vengeful and again if I position myself right, there is no "chase". Just disable the enemy and my allies go in.
For other heroes, I play mk, dk and even riki, I tried it out for fun and I never felt it was useful. This is factoring games with and without oov.
So whats the go here? Is it only realistically useful on specific heroes like CM and thus since I never use her, I don't see the value?
I really think 20ms is never enough to get you out or in a fight and good positioning should solve that anyways (compared to other items like oov, yasha or even euls without the active, that give enough MS to make or break the engagement).