I don't agree with you about Rootstock. It will be a sidechain and will have its own transactions and block time. The amount of transactions per second (about 300) will be a big release on the scaling subject and the block time is comparable with Ethereum. This means that te same smart contracts, DAO's and apps will be possible, but on a way more secure blockchain and with a way more stable currency having a bigger infrastructure. I'm very exiting about Rootstock coming online for the public in Januari and I think it will be a better choise than Ethereum.