I think I can help with this one.
with a fairing you will find a few more options that will enhance your ride and comfort. a fairing will give you a lot more protection around the sides and arms as well as create a very comfortable pocket of wind to ride in. The down side to riding with a bat wing fairing is the potential for buffeting at higher speeds.
The buffeting can be combated by using an adjustable fairing that can be moved forward and backwards, you can also use a windshield that has a flip or flare at the top, the purpose of this is to direct the maximum amount of wind strait up and over you without causing a vacuum behind the fairing that will cause buffeting at higher speeds.
by using a flip up windshield and an adjustable faring you can fine tune the angle at which the wind is deflected up and over you.
as a final step in creating the maximum comfort area behind the fairing you can install wings that are adjustable.
The catch here is that no two riders are exactly the same, some are short and others tall, some have long torsos and short legs and other have short torsos and look like a spider. the challenge is to find the set up that is going to work for you.
With a fairing you have alot more options to control the area behind the windscreen.
If you decide to go with a full windshield with no fairing then you still have to make a decision, do I want to see over the windshield or through it. Take some measurements or sit on another bike and see where you stand now. if you are looking right through the top of the windshield you will not be happy in the long run.
When measuring to see over the top of a windshield you want the top edge of the windshield to be right about at the top of your upper lip.
if it is any higher you will be looking through the edge of the shield 20 minutes into your ride because after a little while on the back we all slouch down like a wilting flower. For most people I consider the top of the lips to be the proverbial G-spot when it comes to windshields.
If you are trying to see over the windshield and want to have the wind go over you as well check out our new road king windshields - which will be availiable in variable heights sometime next month. They have a flip up on them that goes all the way to the vertical position giving you the maximum amount of protection.
If you do decide to go with a fairing, Get a dragon fly fairing, they work great and are compatible with HD windshields and most accessory windshields. They are sturdy during a ride and have great reviews. There are some others out there that are similar and sturdy but I haven't had a chance to play with them yet. I have played with the Memphis shades faring and was not really that impressed.
Heres a few pictures of my road king with the Fairing and without.