With the price of the units and transducers I doubt that anyone would have more than 2 different units on the same boat to compare. Its also time consuming to learn the operations of one unit lot alone 3 or 4 different unit all at once to do a comparison. Don't get me wrong I'd like to see the comparisons also but someone would have to invest a lot of time and money to do it. I have used Lowance , hummingbird, garmin , and raymarine. All have there good and bad points. I settled on raymarine for the following reason. Great customer service, 3 year warranty, in my opinion the best built unit, ease of use, and you get 2d,3d,sidevision, and real vision in one transducer. And again in my opinion ray marine image on the screen is larger and clearer than the other units I used. The hummingbird unit I used wasn't a mega unit and the mega images I've been seeing are unreal. If you shop around you can find a 9 inch axiom with realvision transducer for around 1300.00. And there aren't any black boxes to hook up. If you are serious about buying a raymarine product I believe they have local pros that will take you out and demo the product. Message jig34 on bassboatcentral to set something up.