First, I'm very tall, and so is my wife (6'4"/5'11"), and we don't own or want full face helmets.
The F4 is the third windshield I've had on my Spyder - stock 25" touring, 25" touring, and F4 3+ wide with vent.
As a driver, I can't feel the wind difference between the stock and F4+, however the weather protection is stellar. For my wife, she can tell a huge difference, but the windshield has to be raised to my eye level.
The F4 is much clearer than either of the BRP windshields, provides a different aerodynamic shape, and is almost 2x the cost. Overall, I'd rate it at 4/5, vs the stock at 3/5, and the vented BRP windshield at 2/5.
I wish I could have found a laminar lip to try with the stock windshield - to change the airflow. I've used those in the past with great success.
Bottom line, if you are seriously considering the BRP vented touring windshield - don't. Spring for the F4. If you are modestly happy with the stock 25" touring windshield, it comes down to whither you want to spend $400 for a vent (we don't have bug issues here), and better weather protection. I'll add to this later in the riding season.