I have a 597ci hd di I bought last year that I like very well the only problem is the gps speed does not work well if you like to troll anything under about 3mph the readout will not stay steady even if your speed is and when setting still the speed numbers jump all around I have an older HB161 that has gps speed so I use it also when trolling plus my handheld lowrance asked HB about the speed problem they say nothing they can do was design issue not sure about the 700 models my geuss they don't have that issue also check Walmat on line sometime they have really good deals on fishfinders