I have been fortunate enough to try out the Garmin, Lowrance and the Furuno combo units. They all are new models with similiar prices and all worked great. I found that the design of the Furuno was easier to use especially the sounder. The use of color on the GP 1650F makes the sounder data more accurate and reliable than the others. As far as the seperate units versus the combo, it depends on the boat, the way you use it and your budget. Currently I use a handheld GPS. After using these units, I understand why the dedicated marine GPS is so nice. with the handheld, I have had problems maintianig a fix with the top up or in rough seas. The hard wired, remote antenna units are far more usable. For me the seperate furuno units make the most sense.