"How's it sound" is subjective. If you grew up with Kraco and Audivox this is going to sound fantastic. If you grew up with MB Quart (before they became mainstream) and JL Audio then this is going to sound like entry-level Pioneer equipment.
It's better than nothing but it's not going to win any SQL or DB contests...ever.
There are no RCA connections. The instructions show an amp trigger wire (blue wire, female bullet connector), an AUX output (red,white, 2 black wires, white plug) and an AUX input (3.5mm headphone jack. think iPod/mp3 player). Mine actually has 2 of the white plugs. Both have red,white and 2 black wires but the wires are different gauge between the 2 plugs.
There is a current part # for a "Deluxe Harness" but last time I checked the harness is not available yet. Deluxe in this case has nothing to do with the trim level of the machine. According to the "Deluxe Harness" for the Rzr, this harness provides connections for 2 LED light bars and the radio. There is also an "Ultimate Harness" that provides connections for 3 LED bars, 1 audio device in front and 2 in the rear, and subwoofer connection.
I have no idea if this is the path Polaris will take with the General. Just info I've picked up along the way.
Edit: If I recall correctly the "Deluxe Harness" for the General specifically mentioned "additional audio connections".