Sorry don't know the Gendarme 20 but Royal Scottish is my number one! It is quite similar in construction to Caron Pour Un Homme, lavender on top and vanilla underneath. RSL has more citrus notes I think and a cleaner, purer vibe to it, with a really beautiful vanilla note which holds the lavender just enough to remain fresh. Caron has a little good aminalic dirtyness to it buried right at the bottom, I think (can anyone confirm). I like then both but if I had to choose I would go with the creed.
I hope you know C.P.U.H. otherwise this post is not much use to you, couldn't resist the chance to talk about RSL though.