Difference between "E+ctrl" and "soften (line)"

Hi there,
I am making a model, and I had to “soften” plenty of lines which takes hard work for me, as I have to right-click and select “soften” for many lines - this mouse is not made for multiple clicks.

Since “E + ctrl” also softens lines (and smoothens the texture difference along with lighting and stuff) I was wonder, instead of ruining my mouse, I could just press “E” along with a “ctrl” and the lines would be soften.
Before I “E + ctrl” the top.
After I “E + ctrl” the top.

However, I haven’t attempted this yet, and it seems risky as other times I “E + ctrl” an entire build and lighting did not look so good.
So, seeking your advice, should I painstakingly “soften” the lines, or should I stroll in dark alleys and “E + ctrl” the build?
Thanks and Merry Christmas!

There are two different modifiers for the Erasure (big fan) tool.

Shift key hides edges. This leaves the faces intact and the look of the faces unmodified. This is often useful for visually joining two objects together. For example putting two components next to each other and hiding the edges where they touch can make them appear to be a single unit without breaks in the faces.
Control (or the option key on MAC) soften/smooths edges, which hides the line and visually blends the angle between the adjoining faces. This can make the model have a less faceted appearance. It should be noted that this does not affect the underlying geometry, only how it is displayed, the facets and angles are still present in the model just being hidden by a different kind of rendering on your screen. Eraser with ctrl key is the same thing as using the right click context menu

You can get finer control of soften smooth and quicker use on lots of preselected geometry by using the controls at the bottom of the Display tab. In this GIF first I work with eraser/ hide then eraser/smooth then I smooth the whole thing by selecting it all and adjusting the controls. Notice I move the slider from 0 to about 30˚ to smooth the arc, If I move it past 90˚ it smooths the hard corners of the walls which often gives an awkward look.