I bought a set of NOS gippiemme spoon shifters of the bay, hoping to replace my stolen simplex retrofriction shifters. I notice that these don't really look anything like the simplex do, they lack the little spring.

Any comments on how the function compared to the simplex shifters? Are they actually retrofiction? I've heard them described as such, but they just look like friction shifters to me.

-edit-
I realize I could just throw them on and try them, but I was going to preserve their never mounted condition if they turn outed to not be what I expected.