From the link above, benefits for Silvers on DL:
Not very good.
How many, and how/when can they be used?
Same as above.
Woohoo!
Now that I can get excited about.
Gold only adds a 100% mileage bonus instead of 25%.
So, while for Plats it is quite a generous program it seems, for Silvers and Golds I don't see much to get very excited about here.
Am I missing something?