Just brewed an IPA Sunday. Since our house usually is quite cool in the winter (64-66), I was concerned with pitching enough yeast. I use the White Labs vials, in this case London Ale. So this time I made a starter with 1/4 pound of light DME.
Tremendously active in less than 6 hours. I have never had a batch perk up so quick! I think I am a believer in using a starter now. And much cheaper than pitching two bottles of the White Labs.