I'd go for 1 if there are no side effects.
i'm very scared of side effects. i recall having changed that once or twice over time and that the diffs were very subtle.
I've heard down the line that Gavin and company somewhat regret introducing a difference between 'save' and 'saveOrUpdate', and that given an opportunity to do it again they would not bother with only 'save'ing. In fact, its my understanding that JPA itself only supports a 'saveOrUpdate' concept. But I'm simply repeating what I've heard rather than what I know myself.
Perhaps someone could ping Gavin and he could comment on any nuances between the two that might affect us.