Be patient and give them some time. Reassess your thoughts after about a week with them.
French speakers tend to be very system dependant. You can't just toss them into the pot and hope the receipe works out like you can with most other speakers. Getting the right ingredients is the key to success and that takes some time and effort. But get it right and their dynamics and clarity will reward you like few others can.
I know the Arros well - they will be a HUGE change in sound type. Their treble is not very articulate which affects their overall transparency excessively in my opinion. Same goes for the poor Hawks we A/Bed with my JM Labs - we were surprised at how muddy and confused the Totems sounded in comparison. But, they may be more your taste than mine!
By the way, what electronics are you using? Arthur
Man if I had known you were using an Arcam receiver, I would have warned you about excess brightness with Triangles. I wouldn't care for that pairing either. If you want to keep the Arcam, I would try something like Coincident Triumphs. They are very efficient and can use a little high frequency boost. I bet they would sound much better than Triangles with you amp. Good luck!