Speaking from direct experience, I have one of these straps and have the GS, and with a lot of faff managed to fit the strap once.

I decided it didn't suit so took it off. A few months later I thought I'd try again but I could not get it to fit through the gap, no matter how much work I put in.

It's a real PITA so if you're a fan of quickly and easily swapping straps, then this isn't the strap you want. If you want to battle it for an hour or so to get it on the watch and then leave it on the watch, then it's fine.

It might be different for a standard G10, and I guess there may be smidgens of tolerance difference between watches, but on my particular watch it was a no go.

Luckily it fits the Hamilton W10 perfectly: