I used to be a die hard hummingbird fanatic!
since they were so far behind the 8 ball with their live image and I upgraded boats that already had the Garmin units I decided to give them a try . my transducer for the side/down image is a 36 which is the same as a 56 from what I understand just without 2D which I get from my shoot thru hull transducer for that . I can see so much more on the Garmins at such slower speeds even have picked up stumps, blue gill beds , grass lines etc setting still that I couldn’t ever pick up on the bird unless I was moving at 3 mph or more ! Hope this helps I’d say the 56 would be worth every penny ! Can’t speak for the 54 hadn’t ever had it but the Garmin units work outstanding for me .