I just bought mine yesterday and can't wait for installation, I have heard and seen nothing but good of these units but ultimately made my decision on customer support and here's why:

A friend of mine has a good friend who lost his son somewhere on the Illinois river, (it was a boating accident) and the guy could not give up finding his son, so he was on the water every day in fact it consumed his life to find his son. He called humminbird to get a price on one of these units to help him on his quest and they sent him a 1197 free of charge! Now he had documentation as to his loss and they confirmed everything in depth. He set out to map the area his son was last seen well over a year of looking he found a small child, and 2 adults still inside their cars! All this amongst numerous other findings..... and finally it happened - he found his 19yr old son and his car! "He could not have done it without the support of humminbird and the quality of the unit ".

Humminbird thumbs up! I am not a rep, dealer or anyway associated except the fact I am now a huge fan and as of yesterday new owner of one of their 797c2 SI NVB yeah baby! $1017.00 later, and compared to the garmin I have been scraping by with (graphics - yuck) that cost around $950 I beleive I'll be very happy.