How does a glass lid affect a humidor?

Humidors with a glass lid are often used in restaurants and bars. What are the pros and cons?

The primary advantage in the above situation is that the guest can look inside, choose a cigar and only open the humidor to take the cigar out. This avoids larger fluctuations in the moist micro-climate that can occur when the lid is held open repeatedly for long periods of time while the smoker makes a selection. The other big advantage to a glass lid is that, in most cases, you can read the hygrometer and keep track of the humidity level inside without opening the humidor.

These same advantages are carried over should you opt for a humidor with glass lid for personal use, at home or at the office. This is especially useful for showing your cigars to friends and colleagues.

In both cases the main disadvantage is incidental light, which can lead to the wrappers fading over time. Insofar as the cigars are consumed and renewed regularly, this need not be an issue. Humidors should never be exposed to direct sunlight. This is particularly important for humidors with glass lids or sides.