Use whatever the hell you want. I don't spam with fusion rifles, but I still keep a few in my inventory for different situations. Use the cheapest stuff in the game. Make people mad. Get some fan mail and it'll make you happy. For instance: I was playing rumble in the early days of Destiny. I had just gotten the Invective (no range upgrade). I'm ashamed I used it like a primary that match, but I also used my auto rifle (I run with HCs now). After I won the match, one person told me to get a job. I asked him if the "widdle baby is mad over a game." He told me I was trash, yet he had 6 kills. Anger fuels all weapons in this game. Use them all.