I was aware of xhliu's work before. It's actually a big thing because Ethereum was created with the assumption that bitcoin's scripting language does not allow for state transfers (stateful contracts) and turing-complete computations. The advantage over account-based systems like Ethereum is scalability: Ethereum contracts are one central entity identified by their address, any access on the contracts must be serialised which leads to scaling issues with popular contracts. Bitcoin's UTXO model on the other hand is rather easy to parallelize; but scalable UTXO-based contracts also require a different design.