I had a Tulsa and now have a plus 4" F4. I would not go back to the Tulsa. The F4 does not scratch and I use a squeegee when I gas up. The F4 sits more upright like the stock shield does. With the Plus 4" you need to make sure you get the vented model. With the vent closed it gets real hot. With the vent open you get much more wind then with the Tulsa. For me it was well worth the money.
If you read the posts on this forum back to May, you will see I have posted many times about the F4 shield. I loved it then and I love it now. The std. is the same shape and size as stock. Then there is the +2 and +4. I'm not sure about the +2 but the +4 I have is about an inch wider than stock. I sit in a pocket of almost still air and my wife says she get far less buffeting.
It is scratch resistant and I used to use the scrubber/squeegee at the gas station, but no more. I recently posted about my experience in Teneessee where I did put a scratch in my shield. The scrubber looked clean but it must have had something in it. Now I will stick to the paper towels or micro-fiber cloths.
The shield is the easiest to clean shield I have ever seen. The optical clarity is great. You can clean tar off with acetone or lacquer thinner. WARNING - don't try this on any other shield - it will ruin it.
The best part is how it sheds rain. For my wife to get the full benefits of less buffeting, I ride with the +4 all the way up and look through it. At 5'8" I am looking through 4-6" below the top. I also put Rain-X on my F4. The rains just sheets off. Maybe someday I'll add a marine windshield wiper. That would be cool and you can do it with an F4.
All in all, it is the best windshield I have ever had. Is it worth the money? It is to me.