I have had three Lowrance units over the last 35 years or so. The first one was a flasher unit I bought used for $30, used. It was a Lowrance and worked for 10 years or so 'till the motor went out. Still a great deal. The next one was a Hummingbird, it worked , but was a portable unit and was definitely lacking in features. Sold it later when we bought a Lowrance 527c (I believe that is the number). It had a problem with the transducer not reading surface temp. after a year , could have taken a hit on a rock, but Lowrance sent another transducer, no cost at all, not even shipping or returning the original transducer. Talk about service! It still works fine, been a great gps/ bottomfinder for over 10 years. We just got a new boat, we kept the older unit for our smaller boat and bought a Lowrance HDS gen 3 with a 7 inch screen, also got the structure scan transducer. It has been great! Lowrance has answered all my questions on their help line quickly and have been super helpful with installation questions as well. It replaced a newer Garmin that came with the new boat,that I had for sale on this forum but no one bought it so Craigs list it went. It didn't have maps or the ability to load them from navionics even though it had GPS! The newer Garmins are crap, plugs are cheap and come out easily, downscan isn't downscan, they did not have the rights to that technology and changed it to "clearview", a crappier version of downscan ( a patented Lowrance product) that Garmin doesn''t use anymore because of legal issues (i.e., they didn't want to pay for Lowrance technology). I couldn't even sell it for less then half price even though it was basically new.All this info can be found on the WA. lakes forum under boats and boating topics section, thread is called "don't buy Garmin, etc. The person who wrote it is super informed on sonar, evidently they changed hands and customer service sucks now. Also check out his thread (also in that heading under boats) about sonar interpretation, most informed info I have ever seen, including tutorials. My Garmin was garbage, I sold it. Don't believe everything people say , look for reviews and READ THAT THREAD! It will make a world of difference on how you read sonar. Bob R