I have a Lowrance HDS5, my friend has the Garmin 740s. His radar display overlays the chart. Mine needs the proprietary electronic
compass. (Read expensive). The one I have on the boat already does not meet the requirements. His is touch screen and very easy to use.
Mine is pretty good at "seeing" what is out there. I was able to find a
kayak on the ocean at about a mile and half out. Range is pretty good at about 15 miles or so. Real world use, clear night time looking for ships, land etc. while coming back from
Catalina. He had no complaints on the quality of his resolution. Both units use very
low power. Given a choice, I would go with the Garmin, I looked at the two different units for about 6 months before I made my decision, and it was very close.