I don't think you will get a consistent answer to this question because there is a lot of variablity in snowflake temperment, in my experience. I had a large snowflake moray (~24") for several years that was very aggressive, and a repeat fish eater. I traded him in prior to a move and warned the LFS. They placed him in a tank with other smaller snowflakes and he killed them all that first night.
I don't think this is typical snowflake behavior, as I have had others that were very docile. However, I don't think they are nearly as reliable as a zebra moray for being docile.