The only thing that I have run into that can be a problem with the GW690s is on the III model. They changed a gear that drives the counter and frame spacing from metal to nylon. And sometimes the outer gear teeth get stripped away from a small section. This stops the film from stopping when winding and stops the shutter release from completing its cycle and be in position to fire again. In other words, a useless camera. Considering the number of happy GW690III users out there, this should be considered a rare occurrence. And repair is in the ~$150 range, if you run into a dead one showing signs of this and wonder what it takes to get it working again.
I've not heard any regular reports of the shutter going bad. I'm not certain what the counter is really meant for. Maybe a safety, to be certain the camera is serviced on a regular basis to avoid problems? Legend has it that the camera was primarily meant for tour groups and similar event photography, 'once in a lifetime' things. Preventive maintenance makes sense.
By the way, the counter can be reset quite easily. Judge usage on body wear and such, not the counter. Oh, watch out for signs of oxidation. I've had two GW series cameras that must have been used or stored near salt water and getting inside for cleaning was very difficult because of all the screws corroded in place.
Wonderful cameras, great lenses, great viewfinders. Although large, handles smoothly.