(Express masks are that small yellow piece of masking paper)
These will save you much time and nerves masking canopy and wheel disks. This are very handy and easy to use. I'm very glad that Eduard switched from the masks that were made from some kind of RLM02 :) coloured film to Tamiya type masking tape. Canopies are very sometimes hard to deal - especially keeping them crystal clear after laying and cutting masks.
So the express masks provided inside the kit will definitely fill the list of the advantages.