Do you have to go through security checks to get into work?
The reason I ask is that I have a works car park, but have to stop and show my pass to get through the barriers, so for me a flip-front lid is extremely handy, as I just pop the front up and they can check that its the same ugly mug on the card as in the flesh
I find the Caberg lids fit well, aren't too noisy (but they are noisier than a "solid" lid, and are a reasonable price too