My drops have been stupid the last couple of days. I also got way more purples and 2 exotics but they were for different classes. I got most of these from entrants from the zone right before the earth strike (rocket yard). Pretty much just stick to the outside of the map going in a circle looking for chests and killing mobs as you go. Don't queue up for the strike just to do this and leave. For one, some people actually want to do the strike and for two there's a total of 25 chests by my count... so you should have more than enough chests on each rotation.