Honestly speaking, there is a lot that I can’t really understand regarding this mechanism. So many negative reviews on it. But, as far as I can see in its official description, it comes with 26 jewels instead of the 25 present in the ETA. Also, I might be mistaken, but the finish seems more accurate than on eta. Recently, I tested its accuracy on a TAWATEC watch for one month. It means that for one month (literally) I always wore the watch on my wrist so as to expose it to the most different conditions possible. Sleep, awake, running, walking, working, resting, showering, eating, drinking, everything… Not the most pleasant “activity” to wear the watch constantly but I was really curious about the outcome.
Each day at mid-time I was comparing my watch indexes against an atomic clock. Here is how it worked…the first days the device was + 4 secs. After the 7th day, it achieved +22 sec ahead. Further on, it gained +10 sec. In the 3rd week, it gained +3 sec. So, doing the math, it settled down pretty nicely. For the 4th week, it continued at a -1 sec gain over 2 days, after which it was +1 sec the further 2 days. So, there was a +/- 0-day average.
After my testing period was over, the watch rested for a couple of days with its face up. For this period, it registered + 7 sec. So, a pretty nice result for a Sellita, isn’t it? And for mechanical movement in general. Idk; my own experience was quite promising. Otherwise, it’s pretty hard to rely on others’ opinions, so better do your own experiments and testings