Yeah, whether they're "completely" silent or not would depend on usage and person. I prefer a very noiseless rig so I felt that the TF added too much hiss when used in front of the amp. No problems using it in the loop. Had I been using guitars with hot output I'd probably be fine with it in front of the amp though, but I often use low output single coils.
If you don't mind adding a good clean boost in front of the Eventide, and push it closer to clipping, you can get that hiss down to inaudible.
