Man its going to depend on the style fishing you do. If ya got the money........Cant go wrong with side image. Me personally....I would not have a unit with JUST down image and 2D. The same this can b accomplished with just a nice 2D sonar and alot cheaper. But Side Image is the bomb and is necessary when it comes to open water fishing and even in brush pile fishing. Im not saying that the high def down image is useless, im saying to me its not worth the extra price to me if I weren't going to go all the way to side image. I AM saying you should get side imaging, and that in turn will also give you high def down imaging and 2D color sonar, BEST OF ALL WORLDS! As far as brands....I'm a humminbird guy. Been around em all and I still prefer humminbird. But on that topic....ya gonna get ALOT of different opinions. They all have their pro's and con's and a lil different. But they all pretty much have all the same technology. So that research there will b up to you. May have to sacrifice some things that you like for things that you love! Good luck in your search! I can be more specific in these units if you want my opinions on them. But I don't want to taint ur opinion on something that may benefit you more because of my advice. So ask me anything if ya wanna.