Truthcoin style turing completeness, inside of flying fox, will be far more scalable than ethereum's turing completeness.
One of the major limitations with ethereum is that all the contracts run on the same thread. It is impossible to have different contracts compute in parallel.
If we put oracles into channels we can overcome this limitation, because each oracle only looks at a subset of contracts, but we have to accept a different limitation.
With ethereum it is possible to have more than 2 people share a contract, and to own state between them.
If we only use 2-party channels, then we can only have state between pairs of people.
So channels work fine for prediction market applications, but it wont work for things like sub-currencies.
truthcoin style turing complete contracts can be written in English instead of a programming language.
Truthcoin doesn't have a built-in scripting language, so you can use any language.