I am a big follower of this forum and I have heard many good and bad service stories.Bottom Line. Humminbird and Lowrance both make great sonar units.If one or the other quit making sonar units I would not hesitate to buy the other. I have mentioned a problem I was having with my Lowrence Elite 7 HDI. I have the standard HDI transducer on the front and a HST-WSBL on the back and utilize a SB-9BL switch to go from front to back. I had initially installed the unit and damaged the transducer cable. I called Brian at BBG Marine and ordered another transducer in Sept. 2013. I began to have problems that made me feel the transducer was not performing as it was when new. I called Brian at BBG Marine. He said it could be the switch, but he suspected the transducer. Justin61,and Mvinc(Ricky) as well as Brian felt I needed to contact Lowrance Customer Support. I called Monday at 3:15 and was told by Brad at Lowrance that he felt it was a transducer breakdown and that he was sending me a replacement. I recieved the replacement on Wednesday at 12:00. Tried it out and a world of difference.I have owned a X510c, Hds 7 Gen 2, and an Elite 7 HDI. Remember Humminbird offers the same customer service. You can't go wrong with these or any other brand you feel you like best. There is no best unit just different levels of how well they are understood and set up for use........crappie1133