I brewed my first AG IPA on Saturday, and the results so far have been pretty amazing. I had an OG of 1.062, which is quite a bit higher than the 1.040 - 1.050 brews I've been doing. I pitched Wyeast 1332 NW Ale Yeast that I had slanted, and built up a starter from. I had the fastest starting, and most vigorous fermentation I've experienced yet. I had airlock activity in less than 3 hours, and by the next morning, the krausen was trying to eject the airlock altogether.
Since this was the first time I built up a starter form this yeast, as well as the first IPA I've done, it got me wondering if the huge amount of activity was a more a result of the type of yeast, the starter, or just the higher gravity than I've been used to.