Sam, if you truly mean transitions, AKA photogrey, I like them a lot. It is nice to have the tint when outside working in the sunshine, especially sun on snow. And it is nice that they turn clear when you step into the shop.
The downside is: They are absolutely no good inside the tractor cab or when driving a vehicle. The glass of the cab or windsheild does not let enough UV through to make the lens darken. For that use, you need actual sunglasses.
Progressives, for vision correction, is another discussion.
