Hey Don,
Garlien has an HD-7 I think (pretty sure it's a 7) and he could probably answer some of your questions. That thing has put us on more fish this year than without it for 5 years combined previously.
The side scan is awesome. You'll never go without it again after owning a unit that has it.
I can't speak for Lowrance's competitors as to the ease of use, but the HD-7 seems pretty straightforward. I've never seen the manual for it, and I can manage all of the basic features without too much fumbling. Since it's not my boat, Garlien is always onboard to play with all of the ultra cool features.
