I'm not really a accuracy nut even though I do own a time grapher. I use it to see if some of the older watches I buy need an immediate service. In December I picked up a brand new Longines Conquest GMT and it seemed a little fast. I put it on the time grapher and it was +25 sec. I decided to pass it over my demagnitizer. For the past two weeks it's running +2 both by time grapher and observation with the atomic clock. What I mean to say is it's +2 seconds a week. That seems really good No idea how long that will last but I think it's the most accurate manual I own right now. Better than my two Omegas and my Rolex by far. What's the most accurate manual you have?