I am also amazed at the time keeping accuracy of my 372SF. Although movement winds sligthly stiffer than 6497, I am not sure about if I want to touch the movement just yet or even service it. The timekeeping accuracy is very good. This is how I check.
1. I adjust the time to atomic clock
2. Since second hand is not present I look at the tip of the minute hand under the magnifier when it is perfectly aligned with stick marker. This usually gives me accuracy within 3 seconds
3. I also use Wild Spectra Pro on my cell phone to confirm the accuracy which is between 7sec & 10 sec. depending how I position the watch for measurement. What I found more less matches time graph picture from TD's QC which was -9sec/day.
I don't know if movement maker improved anything parts quality or cleanness & lube, but the movement keeps accuracy well even after 3 days. I have seen posts here where people complained how the watch after 3 days is not accurate anymore.
Day 1: -12sec
Day 2: -9sec
Day 3: -8 sec
I have the watch for 3 days, and have fully winded it once. I did not do accuracy tests at the same time daily, so these are aproximates, but you get the idea.