Buy this car with your eyes wide open and your expectations in line - you'll be happy. Reading the previous reviews for the RDX, I wonder whether some simply chose the wrong car. Don't buy a race horse, and then complain that it eats too much or can't pull a loaded wagon. This turbocharged engine has its quirks, but drive it right and you'll be rewarded with decent mileage and good acceleration. About 21-22 if driven moderately. Is it noisy? A slight growl when floored. How about road noise? Depends on the road. Texas chip-and-seal roads get a little tiresome, but interstates are pretty quiet, and low-to-moderate speed roads are no problem. For me it's the right car - I'm happy.
The ESS sound system is the best, the SH-AWD is simply superb, paddle-shifter, information display, reserved luxurious interior, front seats, headlights, driving position, fold-down rear seats. The iPhone and this Bluetooth implementation are seamless.
Better gas mileage is always nice, auto-lights, keyless ignition (like the Camry Hybrid), a more linear power delivery, better iPhone/iPod integration (although to be honest, I don't think I could listen to mp3's with this DVDA/DTS 5.1 system available).