Flat soaker hoses are more flexible and easier to maneuver around tight spaces, making them ideal for small gardens and flower beds. They also take up less space when stored. Round soaker hoses are more durable and can handle higher water pressure, making them better suited for larger gardens and lawns. Additionally, they are easier to coil and store away when not in use. Ultimately, the best option for you will depend on the size of your garden and how much water pressure you need.