Hi,
I haven't used Swiss,but i understand that is the best base for being undetectable,i have only used French myself.Swiss glued down would be the best,it would be hard to find the edges.
I have found that on the edges,its hard to get a piece down perfect,they never seem to match the curviture of your head exactly,and i guess if somebody touched that area that isn't down properly they will feel something odd.
I had a woman feel a ripple in the back of my piece once when we were in a spa,she didnt say anything but later she told me she thought it was a scar in my skin.
I only tell woman i am dating that i wear hair,when its a serious relationship,when its not serious i say nothing,and if you keep plenty of product in your piece,they will keep away from it.

Regards topcat