Title explains it all. If you haven't read the 4.04 patch notes yet, you should have seen that they nerfed Viper. They decided to make most of their changes to her wall and smoke and not her mollies, despite them being the most busted part of her kit.

• Fuel drain increased 50% when Toxic Screen and Poison Cloud are both active.

Every change is warranted and understandable, but I cannot get behind this one. Not only are both her abilities hard to use because you can't pickup them on attack, but you also have to learn many lineups just to have the ability to smoke a certain place. I think what they were trying to do was make her less dominant on maps like Breeze and Icebox, but that is a flaw on the map design, not controllers. Viper is the only one who can actually play smokes effectively on both maps, primarily because of how large the corridors and spaces are.

To be honest, I expect Viper's pickrates on every map to be reverted to the last buff. They should have only kept minor changes to Viper's kit, not something major as this.