Ignore all of the uniformed posters. Here are the reasons you want to run normal first. 1) Normal mode loot tables don't contain primary weapons. If you've got all the Crota primaries you want and are just looking for armor pieces with better stats or radiant materials, doing normal first will take the primaries out of the equation. By running normal first and then hard, you're more likely to walk away with an armor piece/shards/energy as opposed to a weapon you don't want or already have. 2) Double Exotic drop. Killing Crota on normal has a chance to drop an exotic weapon. Same goes for killing Crota on hard. It's possible to get an exotic drop from both normal and hard on the same character in the same week. I've had it happen myself so I know this to be the case. 3) Crota Special and Heavy weapons only drop on normal. These weapons are more elusive than the primaries so many run normal just for this reason. For example, I had multiple drops for every primary, special, and heavy except the Hunger of Crota. It took many many many completions on normal before I got the hunger. 4) Chests give 2 radiant materials regardless of whether you run on normal or hard and you can only get them once. In normal mode, you can keep someone in the raid and swap to get the chests on all three characters at once. This way you don't forget to get it on one of your other characters and don't have to worry about failing to get it if the door closes or the first chest isn't in a convenient spot when you run through normal or hard on other characters. 5) killing Crota on normal is fun and easy.