I have the 37mm SBGX061. Presume this was a similar size to the one you tried on? Anyway, I think GS 9F movements perform better than their stated accuracy. Mine is from 2014 and runs well within stated spec. It's actually less than plus 3 secs per year so I wouldn't go for the special edition for reasons of accuracy alone. Even this level of precision is slightly over the top because you have to change the time at start/end of BST at which point it's only gained around one second.