Have had the back off this one several times now, each time using my Timegrapher to get it to +3-5 seconds or so a day. Wear it for a day and it seems ok. 2 days later, it's back up to plus 14-20 seconds a day. I think the hair spring has a flat. When I regulate it I move it just off the fault area, but a couple of days later it's slipped back to the fault area and so is back running fast again. Pity, because it's a very nice looking watch. But at least the back is very easy to get off now I've spotted the 2 little flats on the back, like 50 dollar watches have...