Thanks Gents,
So there are a few emperical points to examine:
1. Quality of edge under a loupe
2. Uniformity of bevel under a loupe
Then - if in doubt - set the bevel!
And if those two parameters don't point you in the right direction, you use the Lynn's Magic 8 Ball and ask "Should I set the bevel?" To which it will always reply - "Yes, do so now".
And, from the massive amounts I have consumed about the subject:
1k to set the bevel (some like tape, some do not)
Move to 4k
Move to 8k
Then whatever alchemy you like - 12k, cro-ox, diamond spray, leather etc.
David