I'm speaking from experience here. The Lowrance units are great. They recently had some problems with water intrusion but have resolved the problem. I returned an HDS-7 three different times before they gave me an 8 as a replacement. After the 3rd one, I started dealing with the southeastern sales director to get the problem resolved. I have since taken a water hose to it and I also got caught in a bad rain storm a couple of weeks ago. As of July, they have fixed the water intrusion problems. As far as the difference between the eagle 320 and the Lowrace, I only know of the plugs on the back being different. They have the same detail as long as you use the Navionics chip. The Lowrance may have better base map, but with the chip they are both excellent.
To heck with work, lets go fishing.