In Spectrecoin two addresses: one ordinary, the other anonymous. All transactions between anonymous addresses are anonymous. Nobody will know from which address and on what payment was made. You can not see the IP address of the wallets either. Therefore, it is certainly not surprising that in a darknet someone is using Spectrecoin.
What did you imply? Is that mean we have rights to choose which type of transactions we would like to do (ordinary or anonymous)? Personally, I think most users will use anonymous functions if transaction fees for both types are the same.
That might not be true in every single situation. If you are merchant for example things could look differently if they are forced to have transparent accounting data with information about their customers. That's why Monero won't go mainstream in the official e-commerce world.