While the damage is increased, making it easier to kill enemies with tough Armor, it still retains the slow mobility and attack speed from its original version, meaning that you will have to catch up to the enemy with a weapon with higher mobility, or else you will get killed because of the mobility being one of the lowest in the game. With it's slow mobility, you can easily take out the enemy with even the Pistol, simply because of the slow mobility that the Chainsaw UP1 has. Just don't get too close to them.