No, Auto Rifles and Pulse Rifles serve the same function. The are mid range and focus on putting bullets mid range. One is slightly more accurate, the other puts out more bullets. However, they do serve the same purpose. Tiny differences, nothing significant, especially with the low fire rate auto rifle. Elemental weapons deal more damage to shields of the same type, while kinetic deals slightly more damage to red health bars. For all intents and purposes, they're the same, no significant difference. Elemental guns will only be effective vs 33% of shielded enemies you come across, against all other enemies your kinetic is the better choice.