Question: Why Is the "Connect to Replica" mode preferred?

Hi,

Sorry if there's an obvious answer, but why is the preferred mode to connect to the replica? I couldn't see in the [Docs](https://github.com/github/gh-ost/blob/master/doc/cheatsheet.md) the exact reason for it, but it would be helpful to determine which mode we should use in our environment.

For us, we are able to use both methods. But not all of our systems have the proper configuration for ghost (log_bin, log_slave_updates, binlog_format).

While we could schedule a maintenance window to make those changes, I'm wondering what would we lose out of we just ran from the master.

Thanks!
-w