TN vs PVA advertised response times

[AdamK47]

I currently own a Samsung 204B with a listed response time of 5ms. It doesn't say if that response time is black to black or gray to gray. I do know that this monitor has a TN panel though. When looking at S-PVA it lists gray to gray response times. How comparible are the advertised reponse times of a TN panel to that of a S-PVA/PVA/MVA panel?