I just bought a Lowrance Globalmap 3500w/chip. It's a color unit. I played with it in the store for a couple of hours first. The most user friendly unit I could find. I also bought a Raymarine DS 400 sounder. Perfect for my application. I like one unit to do 1 job. If you loose your multi function unit, you're done unless you have backups.
Right now with the $175 rebate from Navman it makes the 5500 a great buy at around $400 for a color unit. I don't have one but if I were in the market right now I know I'd be looking closely at one.