The payment will not be traceable.
Let's say TPB accept Silent payments. Someone sends them a donation, which confirms on-chain. Nobody else can know TPB is the receiver, because they can't know which on-chain address belongs to their Silent payment.
But what if I send a very specific amount. Then I could just look at the next block, find that amount and see to which address it is send in reality. So at least the sender can very easily verify the real address.