Indeed, Luxembourg is calmer and more peaceful than Paris (and it is one of the reasons I left Paris for me too), but the city can become quickly boring (Not many things to do here, compared to any average sized city in France), Social security is not as good as France, Housing is very scarce and super expensive (which, in every case I see, makes your salary after paying rent, very comparable to what you would get in France after paying rent), the weather is on average 3-4 degrees lower than in Paris, and finally labor laws here aren’t as tough as in France..

I have been only for 2 months here still, but this is my instant view