Yes it is. I've been out there and while neither the shops nor the food places are upscale, they are better and more interesting than anything I've seen at the airport.

We went there from Paris so I can't address acces from CDG from my experience. However, there's a short bus ride from the RER station to the shopping area, and the bus came every 15 minutes or so on a weekday afternoon. Allowing for the RER train, the bus and going back through security, this is not a trip for a 2 hour layover. My guess is you could take a cab from the airport and back for $10 Euros or so each way, though I didn't do that either so I am guessing oin cost and also on getting a cab back.