I have the 797 and love it.find lots of structure with it. also am learnin to read it better to find different types of bottom.with logs laying down or leaners the other fish finder's miss,, I like it real well,have the 777 up front on the trowling motor, excellent unit.
now one thing I dont like about the maps I have navonics,and there not to good,not bad but not to good, on my garmin I hav hot maps and they were great.... good luck