Looking into buying an aftermarket ZG windshield for the GS. I'm touring about 1,200 miles in early July with  number of experienced riders and we will be doing about 70/30 highway/2-lane. I'm 6'0" tall and have been looking at the touring and double-bubble models. My questions are;

Whats best for my application? Should I be looking at the touring model or is the double bubble better? If so in what scenarios?
Light smoke or clear? Does the tint significantly decrease the visibility esp. with a higher shield?

Thanks,
Jon.

I cant really tell you whats best for you....but I can tell you I have the tinted double bubble and it suits me fine on long and short rides alike, I'm 5'10 so a little shorter than you.  I've done a few 800km trips and it works well.  To note, I bought the bike with this already on it, BUT I have ridden a buddies GS with the stock shield and its noticiably better. The tint doesnt cause me any issues. 

Clear touring screen vs Smoke double-bubble:

I'm a bit shorter than the OP but don't find the D-B screen hinders vision. If the touring screen was tinted it would have. I find negligible difference between the two for wind buffeting but both are a bit better than the standard screen.

Standard vs Touring screen:

I have the touring model in clear and dark smoke.  Never tried any other models but I'm happy with the touring model style.  In fact I'll be selling the clear model shortly, if you're interested let me know!

I have the clear touring with a laminar lip on top of that. I found that the touring screen drastically increased wind noise by putting the blast right at the base of my helmet instead of my chest. I added the lip to bring it up to about visor level, which is  less noise, but still more than stock. I still prefer it this way because you don't have the fight the wind on the freeway, I just always wear earplugs and then the noise doesn't matter. I am 6 foot.

Smoke touring for me. Smoke just looks better and keeps sun off of gauges.
For me the double bubble resulted in too much wind popping at my helmey.
Then it does depend on your height and riding position. I have Euro clip ons so my position is lower and forward compared to using stock bars. Double bubble probably would have been OK if I had stock bars on.

Oh yea, I also have bar risers, so I am sitting upright. I think if I had clip-ons it would be dead silent under the touring screen + laminar lip.