Vanity FairWomen's Ego Boost Push Up Bra, Adds Up to One Full Cup Size, Underwire Push Up Bras for Women

How is the padding for this bra??

is cup size with or without "add-a-size" considerations?

Does anyone have any issues with the straps constantly sliding down?

Hello dooes this bra have alot of push and padding for smaller A cups?and does it give a natural shape and form under tight low cut tops?