I bought my KW 312, with the ST2555 movement in May 2014. Within two weeks, the stem inexplicably broke while inside the watch while I was gently giving it a startup wind. I sent it back to sead for repair. I got the watch back in late August with the the stem fix, but it is still a stiff winding movement. It does keep decent time on my wrist, but the PR on my watch is lousy. After a full day on the wrist, I could take the watch off at 8pm and it's dead by 11:30. A 3.5 hour PR is entirely unacceptable IMO. Clearly, the watch needs a full service, but due the lack of any replacement parts and the fact that some of these in-house asian movements are hard to work on, I haven't found a watchmaker in the US willing to do the service. It would probably cheaper to get a replacement movement anyway, but installing the faux bridges and decorations is a PITA. While the ST2555 does look a lot more like a the gen p.9000 than the decorated A7750, the A7750 (non-chrono) is a much easier movement to service and parts are easy to source.
In contrast, I have have had a Noob Pam 243 since late 2013, which has a non-chrono version of the A7750 that has never been serviced. That movement has been perfect. It winds smoothly, has no rotor noise at all and keeps excellent time. After a full day on the wrist it has a 40+ hour PR. I also have had a KW Pam 390 with an A6497 movement for 1.5 years. It's also never been serviced, but winds smoothly, keeps excellent time and also has a 30+ hour power reserve on a full wind (possibly longer, but I haven't checked recently).
Obviously, other members have had great experiences with the ST2555 and, given the significant difference in price when compared to the A7750, I might try another ST2555 powered watch--provided it was less than $250. If did buy another ST2555, I would ask the TD to test the power reserve to make sure it gets at least 25 hours and to check to make sure it keeps reasonably accurate time (at least +/- 15 secs a day). Clearly, I am not asking for a watch that meets COSC standards, but it needs to be in good enough shape that I don't have to have it serviced (since it's not a watch I can get serviced in the US). On a more expensive watch (where the ST version is over $300) that I expect will be a keeper, I would probably spend the extra money for the A7750 (especially if it's a closed case back).
Is it better to wind it manually or to move it?
