I just purchased the 270 watt EX system from someone who replaced theirs. (Yea Ebay) The one I have currently is a stock Honda CD unit, and with the addition of 2 additional speakers (only came with fron speakers), it sounds VERY nice. FYI the speakers are Infinity 652i's. I'm only upgrading because I like the look of the EX unit, and the additional subwoofer and tweeters.
If anyone is interested in buying the old one, let me know.
Pink Floyd, 'Dark Side of the Moon' sounds absolutely incredible even on the stock unit.