If you don't mind a little extra wind in your face. I love my 6" windshield. I prefer to look over than through a windshield. Plus, the bike looks beter with a 6 or 4" windshield IMO.
I have a 9.5" Clarks Custom Halfmoon Wing on my Ultra and love it. I'm 5'9" and see over it with no more wind than the stock shield. It looks cool too!
Have a 6" windshield on my EGS and like it. When I had the rear end 1" low and stock height front end, used to get a nice "pocket" to ride in. One time I tried to spit a piece of gum out at 80mph and it stuck to my pants because it was in the pocket. Since I lowered the front end there is more turbulance. Changed the '99 mirrors to streamlined mirrors and it helped on the turbulance.
I've got a 6 on my EGS, also have a 4, stock, and a 10 inch, so I can fairly say the 6 is on 95% of the time. Rode round trip to Daytona, about 1800 miles or more in October. Kept telling myself to put on the stock, or the 10, and ended up leaving the 6 on there. Provides a good amount of protection and just looks better than anything else IMO.
I bought a 8 in clearview w/recurve.
I'm 5' 9" and works well for me. I have a clearer view of pavement and the recurve pushes the air up over my helmet.