I would like to know the distinctions between these following words and phrases when they express approximations.
I will be there in about an hour.
I will be there in around an hour.
I will be there in more or less an hour.
I will be there in an hour or so.
After writing these down, I find the second one and the third one somewhat unnatural. But they are only for demonstrative purpose.
What is the difference in terms of meaning?
Do they have any differences in other aspects? like the kind of object they approximate or something else.