I have the gvs and a uvex. The good thing about the uvex is it provides better protection for the neck - the extra plastic on the bottom gives better support if it is hit with a chuck of wood flying off the lathe (yes, it happens). But - the downside it that with the gvs respirator gets in the way of the uvex coming all the way down to your chest. You lose neck protection. If the face mask is not all the way to the chest, some chips have a way of bouncing off the chest in up into your face.
With a GVS resp it will come down all the way to the neck. But the protection at the bottom of the shield is not as great as the uvex. I have a large size GVS - maybe the small or medium do not have this problem???
Good thing about the GVS is easy to clean - just remove the filters and dunk it in a sink with soapy water. I blow the filters out with a air hose (low pressure). It’s three years old, the straps are a bit stretched out but it is in good shape - I replaced the filters once.
So when I turn heavy items (>5lbs) I use the uvex and a paper face mask. For <5lbs (or once the item is < 5lbs) I use the GVS and the SAS shield. Paper face masks don’t work very well for fine dust when sanding - the GVS does.
The field of vision is very good for both face shields.