I changed the original strap on my oldest G-Shock (the one I wear for work every day) for a new "Nato style" one, but since the original strap was also some kind of Nato copy, I didn't have to buy the adapters.
The original one was good, but a bit bulky, and after about 15 years of use it was getting pretty worn out (and a bit smelly, even after washing it thoroughly ...).
So today, first day at work with new strap, and I must say, I like it a lot, very comfortable, and not as bulky as the original one.
P.S. I went for the 24 mm Nato/Zulu strap.
So, here are some pics with the original strap:


And here with the new one:


