I'm also the same physical size as the OP. '17 CVO SG with the 5" KW shield. I bought the 6.5" KW, but it was to tall. Always stretching to see over it vs right even with top edge blocking way too much road, so I then bought the 5". I like the looks of the stock Windsplitter better, so I put it back on 3 weeks ago to retry. I wear either a do-rag to keep sun off my scalp or a headband to cover ears to block out wind noise. I noticed right away that the buffeting was always making my do-rag top flap from the wind and work up a little. Constantly readjusting it. Also slightly more wind noise. Gave up and put the 5" KW back on. The KW has a little more flip than the stock WS to direct air up higher. All is good now, my do-rag stays put. I also have a better view of the road over the sides while in corners with the KW vs the stock Windsplitter.
I also bought a stock SG seat I thought Id want for long road trips as the CVO seat isnt as comfortable with its less padding, but it moves me an 1" higher. Then the 6.5" may be a better choice with that seat.