For the extra $100, it just wasn't worth it to me. I had BT in my last boat through the deck, and it was great for the fact that I could play music off my phone and still have it out to take pics and text. But as it is, if I'm running music off my phone it's in the car dock that's suctioned to my windshield and that's good enough.
We have a lot of options for audio as it is... and typically it's been the Ipod or using a USB flash drive.
My biggest gripe with the BT on my last boat is that every time we cranked the ignition, it would interrupt the BT signal for that millisecond and in turn make my phone PAUSE the music player. Not a huge deal when I'm driving, but it's a pain when I'm in the water and that happens and I have to talk someone through un-pausing my music on a phone they can't really see the display of well in bright sunlight. Bottom line is that BT ended up being more trouble than it's worth.
You can see my phone dock in these pics: