In Ethereum, the caller specifies the gas amount beforehand to ensure that the execution finishes. In the presented bitcoin-based solution, the caller prepares the transactions beforehand that finish the execution; it then publishes the transactions.

> At this point, what is the benefit I am getting from having this "contract" at all? I would be better off with a just serializing the state of my machine and putting it into OP_RETURN, getting a much smaller blob to store on the chain. > Article essentially uses bitcoin blockchain as a database

This is just plain wrong and not at all what this article is about. In the article, a script is developed that enforces state transfer by the specified transition table, i.e. only a specific set of bitcoin transactions are allowed on the state, namely the ones from the transition table.