Advantages: Survey documents (like all surveys) collect information and feedback from participants that are in this case, engaging with a user interface. Questions, both specific and general, can provide opinion and praise/criticism regarding various aspects of an interface including but not limited to: ease of access, navigation (on-screen/off-screen), commands, hardware/peripheral design and graphical user interface (GUI). Results collected can improve on the shortcomings of an interface if needed.
Disadvantages: Survey documents, as they can be written on, have to be collected physically whereas surveys done via an interface (i.e. computer) can be electronically collected. Additionally, time to evaluate results and trends from surveys are significantly dropped if depending on the latter while the former maintains these problems.