I did.
At vet0 ost was 3, 5 and 10 seconds behind.
At vet3 ost was equal or superior, depending on rng.
Distance was about 20 and since ostwind creates yellow cover, that's what it was shooting most of the time after 1st attempt.
Targets were rifles for ost and volks for centaur so both shoot at equal number of models.
Unless the Ostwind gets one or two lucky AOE hits, it's behind on the Centaur in pretty much every situation or at best it's on par (vet3 Ostwind vs vet0 Centaur). In all my tests the vet3 Ostwind only wins against vet0 Centaur in TTK when fighting infantry behind heavy cover because it destroys said cover faster.
Try infantry behind semi-indestructible light cover such as fuel barrels and the Ostwind can't kill them at all because it keeps hitting the wrecked barrels. Centaur meanwhile shoots at models so it has no trouble killing.
Anyway the fact that a vet3 Ostwind is even comparable to a vet0 Centaur is enough reason to buff it.