No one thoughout recorded history, apart from assorted nuts, has ever believed that the Earth was flat;
This is waaay off-topic, but your statement isn't true. Yes, many learned people suspected the Earth was a sphere of varying sizes for thousands of years. And Columbus didn't have to convice royalty the Earth was round. But the average extremely uneducated and superstitious person of the day really *did* think the Earth was flat.
I know all about snapshots and all that, by the bye. It's -performance- which is the question.
Theoretically, local disk should always be faster, if everything else was equal. But everything else isn't equal... it's certainly possible that the overhead of the local UNIX software and hardware is so great that it offsets the advantage of local disk. It all depends.
Bruce