I am going to upgrade my electronics to include side vision.  What is the difference between the gt54 and gt56 transducers?

There are a couple good comparison videos out there,  like

I have a gt52 on my kayak and gt56 on my boat and I see a huge difference.   Difference between gt54 and gt56 is not nearly as great, based on the videos I've seen.... but there certainly is better definition from the gt56.

Exactly. The GT56 has a little better imaging than the 54 and I believe it can go deeper as well. I have a 54 on both my Echomaps. Not a big enough difference for me to even consider changing to 56’s. 

Thanks so muck