I have the 10 and looked at the 9 in the store the other day after months with the 10. The 9s screen looked great and would have been just as usable as the ten. But, that extra inch is diagonal so it does add quite a bit of screen size and for my eyes everything helps. Also the difference in price is based on the transducer upgrade that is included with the 10 over the 9. I knew my pricepoint considering the sale of my old unit and a few other things I had sold so rather than by the less expensive one and always wondering about the larger screen I just went for it.