I just bought a new fish finder from Lowrance. I went with the Elite5 HDI. I had the same problem as you did with figuring out what each companies proprietary jargon meant. Basically the answer I got was that the CHIRP technology transducer means that it can be highly customizable.
It can be set for shallow, deep, slow, fast troll, saltwater, freshwater, on and on. Many of these functions take some time getting used to. I went to bass pro and ran one of there's for a little bit and could find, on DEMO MODE, I could get the fish to disappear and reappear using different settings. once I felt fairly comfortable that I could do this in the store I decided to go for it in the real world.
Now that I have one in the field I have messed with it even more. I have it set to do the type of fishing that I have been doing, slow trolling for crappie. Although I did restore the unit to factory settings a few times so that I could start over.
IMHO. Its all a bunch of bullshit to sell product. The chart plotter add-on called navionics was very worth it. I can see very detailed bottom contours which has proven very useful. Also after much adjusting within the unit I almost exclusively use the downscan image overlay option. I think this works great to determine what is going on underneath me. While slow trolling I was actually able to determine a fish following after my jig before it hit.
Let me know if there is anything that you would like to ask further about the unit. I would be happy to investigate with the actual unit to answer any questions if need be.