Benefits of 4-Wheels
Stability: The two additional tires out front add another 7-1/2" to the width of the front part of the frame, making it slightly more stable than the 2-wheel model.
Mobility: The Quad-Wheel Kit allows you to maneuver the unit with a simple push/pull action, rather than the tip & push/pull action of the 2-wheel cart. However, it's important to note the quad-wheel kit does not have front wheels that swivel. To change direction, the user must slightly lift the front or back wheels to turn the unit.
Balance: There is no balancing involved with the 4-wheel model. The 2-wheel model requires you to balance the unit while pushing or pulling it to the desired location.