Using get wouldn't really change anything because the first run will have to populate the fields that are new for every single record. But it may be more effective for successive runs where only a small portion of the records need updated. I haven't tried to do that. However after the first run that does change every single record the following ones aren't nearly as slow anyhow.

It was mostly the first run on the system that caused concern. (such as when It was moved from test to production)

The initial run may be 5,000 records. Following runs are only 200-400 records. Even still breaking it into smaller bits and running it overnight works just fine for me in this instance.

But you never know. Your response may help someone else down the line.