A lot may disagree and that's fine. But if u got the money...go side image with GPS. If that is too expensive....go with 2D with GPS. Either way you go...GPS IS A MUST! There is some benefit of down image compared to 2D but not worth the difference in money in my opinion. Because if it is beneath you...2D and DI will both show u something is there. The DI will show you a much more detailed image....other than being just plain cool....u don't necessarily need to know "what" is there you just need to know that there is something there and is it holding fish and 2D will tell you that! Side image on the other hand....WILL ALWAYS BE IN MY BOAT! I feel like I cannot catch a fish without it!