When I was approaching the end of my career in shops, around 1975, it had gotten to the point where EVERY (almost) CB750 we sold was loaded: Windjammer, lowers, bags, rack and top box. Calafia was another very popular brand. Couldn't keep the stuff in stock.
I couldn't understand the attraction and wouldn't have had one. Actually now that i think of it, my current CB had one on it in 1974 when i bot it used, and within a week i had sold it.
The jammer is a bit of bulk understood. But my FJR has a trimmer, yet full coverage fairing, and it makes such a huge difference in limiting fatigue and staying warm.
Even a simple handlebar shield makes a difference.
So if one is using their CB for real riding purposes, a jammer would be a real option.