Thanks for the response Bob. Your experience of being not able to perceive any sonic differences has pretty much reduced my level of enthusiasm in going ahead with the project that could possibly ruin the ceiling after that (in an event I don't hear a difference and need to dismantle those panels). Will see if I can find something to prop those panels temporarily, just to be sure if they are able to bring some benefits before I permanently fix them to the ceiling.
Cheers.
Cheers.