Regarding the dual layers; one is for accounting and the other is for computing. No other crypto currency has a dual layer system. You can mess around with the programming layer and not affect the accounting layer. For example Ethereum has proven to be a great blockchain for dApp programming but it has been terrible to send money around as Steemit, NEO, XLM and others do it in seconds, Ether can take hours, Cryptokitties clogged the network. Everyone and transaction on Ether is equally valued, there is no priority except by spending gas but anyone can spend more gas even if they aren't heavily invested.

Cardano can assign more value to higher priority, more valuable transactions and a lower value to something less important, more expensive to maintain or something which isn't necessarily legal. This ties into the condenses model where more valuable users would hold more stakes than less valuable users. The proof of stake is also how they reach consensus, whomever has more is more likely to create the next block. No wasteful mining.

Edit: the dual layer has already been established, from the start. Cardano layers are similiar to the TCP/IP protocol layers of the internet. Having one layer is really unsecure, it's better to have two or more as other layers can function perfectly fine, while the other layer is being upgraded or worked on. Just imagine the likelihood of the us military ever sharing a blockchain with Cryptokitties- that's Ethereum.