If Bitcoin is blockchain V1 and Ethereum is blockchain V2 then it is being said that Cardano is blockchain V3. Cardano offers scalability and efficiency that cannot be matched by PoW blockchains. The heavy chain weight, cost of transactions and energy consumption are all barriers when it comes to scalability of PoW based coins. Cardano uses a new PoS algorithm (Ouroboros) which claims to be provably secure, energy efficient and more scalable due to the energy efficiency and low entry costs in order to (mine) stake.
I think that Cardano is going to be huge in the future, it promises to be both, scalable and spendable, there will be a Cardano card that can be loaded with ADA and then spent in local currency.
It is new(ish), it is cheap (300 satoshis on bittrex) and its going to be a revolution in cryptocurrencies and accessibility into cryptocurrencies.
Looks interesting. Still waiting to see anything special with ethereum, ripple or Eos;they all claim to be disruptive, but to me, in daily use just the same as BTC.
I think that PoS is going to take off big time in 2018 mainly due to environment and accessibility issues. As a day to day usage coin BTC confirmation time and transaction costs are a barrier which means that although it is and always will be a great asset and store of value, it is not realistically tradable for everyday items.