I've been using my Fusion IP-700 for the entire year (got one of the first ones in Canada) and I must say I love it. I replaced the cockpit speakers with Polk and left the stock in the cabin as we are rarely there except to cook and sleep. The ability to set relative volume level's per zone (up to 4, but 2 with internal amps) is fantastic. Say I set the cabin to 5 and the cockpit to 8, then when I turn up and down the volume both area's change but maintain their relationship to each other. Very easy.
My one disappointment was the NEMA 2000 connectivity - I hooked it up to my network, expecting to be able to control it from my Simrad NSS-7, but it doesn't work. The Simrad only works with the Sonic Hub, which is made by Fusion. To get around this I plugged the IP-700 into a cheap wireless router and use a second iTouch with the Fusion App to remotely control all the features, from anywhere within range.
The sound is good in my books. Also, no need to plug in any wires - you can insert an iPod into the radio or a USB stick and they remain hidden.