Any reasons not to look at the Ether fork as a good prior example?
In the Ether fork, ETH was the "status quo" coin. It was development of the network which people perceived to be against immutability and potentially against the original Ethereum platform.
In this Bitcoin fork, the original coin is still the status quo coin. If we had an ETH/ETC scenario, it would be reversed because in Bitcoin, perceived security tends to matter to people more than perceived upgrades in the technology. Perhaps this is because Bitcoin is the "main" coin, and others are more of a testing ground.
What would be comparable is if there was a low consensus hard fork to 2MB blocks on the main chain.