Mainly in the strike playlist for me. I've had a handful of 300s drop that way, plus lots in the 290s. The grind between 295 and 300 using those blue drops is pretty tough though. Tip: play the strikes successively to take advantage of the drop buff, and put on a Three of Coins for bosses on those strikes. We were getting great exotic engram drops after we got several strikes in a row in yesterday.