Mark 4 DSI

I am considering a Lowrance Mark 4 DSI. Does anyone have experience with this unit; if so what are the pros and cons? Would the color unit be that much better? I have a 16 ft Lowe Line with a 25 hp Evinrude, so I don't cover a lot of water, but would like to know when I find a good brush pile or an underwater tree. I just can't spend a lot of money on locator. Thanks for your input.

no experience with the Low mark 4, but if you are wanting/needing 2d sonar in addition to the DI, the Mark 4 does not have 2d, the HB DI units do have 2d