No stacks because it took me way too many tries, although I didn't have to skip very many packs, except for the ones on the level right before the Diablo fight. I also switched Nerves of Steel for Boon of Bul-Kathos because waiting the 2 minutes was taking too long.
I don't think I could have cleared Act 4 as easily using a defensive build, since with 40k DPS and Leap+Iron Impact/Ignore Pain up most of the time white mobs become trivial.
Also my gear wasn't very expensive, probably around 2-3 million per piece. The most expensive item are my pants which I bought for $40 off the RMAH (I've made a little more than that so it wasn't a big deal).