Hey Grnfinger,
No 4.5 stable but I have
been there with 1.44vcore to creep around. I'm doing same as you now, finally Prime and Occt stable at 4.2ghz vcore = 1.43 - High!! But I have yet to back it off or fine tune.
What about a table or a template with voltages etc., so we can all compare results?
There's a thread doing just that at ocxtreme which might interest you -
http://www.ocxtreme.org/forumenus/showthread.php?t=2453
What are your voltages for 4.3 stable? What stability test method did you use?