The Eagle 480 has only 1500 watts peak to peak.
The Lowrance 480 has 4000 watts peak to peak.
I do not know if the difference in the power is important to you. There is a difference in the two units.
Think the difference in Power watts is that one will get better readings in deeper water than the other. As I understand it, for most bass fishing usually 30' or less 1500 watts is plenty. For my money, the pixel count is the key feature and both these units have 480x480 pixels.
Yep, I think that is true also.
I don't fish much more than 35 feet most of the time. So Power Watts is a waste for me.
Now Color (for the Sun Light viewing and easy of interpretation of density (hard versus soft objects, size of fish and type of structure), Pixels for all units (clarity of screen, kind of like HD versus Analog) and for the Side Image units from Hummnbird screen size is very important (screen size of the Side Image units because you're looking at SO MUCH MORE than regular 2D).
But Power Watts does not do much other than let you see way down.