RPX stands for Regal Premium Experience. It's a theater with enhanced speakers, screen, and projector for a more enjoyable viewing experience. Think of it similar to IMAX.
It's worth a try. I personally liked it. Everyone is different. Give it a go and let me know what you thought.
It's the best sound they offer. Also you get a seat upgrade and assigned seats when you buy tickets.
Personally, I see no added value compared to a normal screen, unless it's available in 3D.
Thanks! Your answer is awaiting moderation.