I have the deflecto cup holder and use it more to hold plastic bottles, or light drinks in plastic cups.
I'm a little nervous to use it with a glass cup or a heavy cup in case it falls since it's not very sturdy.
Would work really good if you have a shorter desk next to a taller desk for the bottom to sit on, then I would use ittfor heavier items and glass items.
Pros: nice design.
Con: not so sturdy.