I assume it has the same core components as the Sony Nav system so I would have to say a couple of things. The system may be rated at 780W but if you know anything about factory stereo systems this is the RMS wattage. The bass is not bad, but it will never amount to a JL Audio 10w-xx subwoofer.
In the end it is, in my opinion (after owning approximately 20 vehicles) a very good factory installed system. Additionally the actual output wattage would be approximately half of the quoted wattage.
If you want a better sounding system then stick with the standard system and then dump $1500 to $2000 for a custom upgraded system.
I think it's fine. Yes I wish the bass went a little louder but man I can't complain about the freq response. I put in a bass CD and man it hits low, smooth and flat response al the way down. Just can't hear it as well once you start her up and moving down the road.