While I don't care for the looks of a windshield on my bike, I have a detachable that I use in cold and/or rainy weather or if I'm going to be doing any extended super slab riding. It makes a big difference and helps to make the rides more enjoyable. Once I get to my destination the wind shield comes off.
It depends on what's important to you, form or function?
I had one on my 2002 FB. It was very handy when it was cold outside. I would detach it when it was worm. I got my from HD. I had one that I was able to see through. So I would get the most wind protection. You either get one that you look over or through, never in between, it will drive you nuts. If you ride all year long then it's a must have.
Been riding for a long time - Never had a windshield.
Bought my '93 FLSTC - It came with one. Rode it for about a week and then took the windshield off.
Rode it for another week and put the windshield back on - It's still there
Never had a shield in my life until I bought the RK. I never thought I would use it. Then I went on a long highway ride with it on and could not believe the difference. Then I rode all day in the cold and could not believe the difference.
While I absolute love the way it looks without the shield, it is amazing to ride with it on.