Electronics size upgrade?

I'm about to upgrade my electronics. I'm looking at adding the HB Helix Mega SI/DI Gen3 to my console and a HB Helix 2D Sonar & Mapping to my bow (connecting it to my console unit so I can see my SI/DI at the bow unit too). So my question is, is the 10" unit worth $300 more than the 9" unit. Initially I was thinking that $300 is a lot for just one inch more screen but I've read so many times that people say get the biggest screen that you can afford. Would that one inch make a difference or are people mostly talking about going from a seven inch to a 10" or bigger upgrade?

Yes. detail and resolution will improve. If you can swing it, I would go 12"...even better detail, clarity and resolution.

If you are serious about screen size, skip the mega. I HAD mega imaging...then after a few weeks I realized I was not using anything but 455. I haven't switched my graph to 800 in over a year.

Yes. Size matters!

FYI, looking at your Side image and down image from the transducer on the back of the boat on the bow unit is not productive. You are fishing at the bow seeing what has already left behind the boat.
You will want to get a unit with DI/2D at the bow and mount the external transducer to the trolling motor unless you have the Built-In MDI transducer on your trolling motor then you would purchase only the MDI Control Head Only.

Thank you for y'alls input. I will check my TM and see if I have the Built-In MDI transducer.

Bigger is always better in the screen size! Easier to see and AWESOME resolution.I just ordered a Garmin Echomap Ultra 126SV.Now I will have a like new Garmin 93SV to sale.