I like Down Image units (with dedicated transducer crystal for down imaging). Coming from many decades of using b/w 2d sonar units & jumping straight to a color DI unit was an eye opener to me. Took me awhile to get it dialed in how I wanted it, but once I did get it that way ....

My current unit (Hook 7) has 2d Chirp & DI, and the ability to blend the two together at the same time (HDI concept). I was never a big fan of 2d sonar, and even less of one after I got my previous DI unit. I normally just used the whole screen in DI mode (800kHz & blue palette) on my previous unit (Elite 5 DSI) and continue to do so with my Hook 7.