I have an older (mid-90's) Curtis soft side on my NH 2120. I really like it in the woods as you don't get whipped by branches so much, etc. But re your post, the main reason to take it off is to see out better. There's the reflection in the front glass, depending on where the sun is. There's the corner posts in the way. And in the bad weather there's the doors that distort the view. I only use the right-side door as it's too much trouble getting in and out otherwise. In all, I'd 'way rather have it than not (bought the whole rig second-hand) for the sun protection and security in the woods. But I can relate to the freedom my older rig had with no cab.
Of course you learn to get along with what you have.
Jim