Not really unless you know some inside info. Most probably you refer to Confidential Transactions, which RingCT of Monero was based on. The privacy advantage of RingCT over plain CT is that you can even hide the transaction amounts of IO.
Really? I haven't heard about this. I'd love a link if you have one.
Note that Confidential Transactions (CT) are a different technology. While ring signatures hides sender/receiver identity, CT hides transaction amounts.
Confusingly, plain CT actually uses ring sigs as part of the crypto, but not the kind that hides sender / receiver, rather as part of the commitment scheme.