I tried three shields on my F3-s.
Shields are a highly personal thing. Everyone is a different height, torso lengths are different, your weight might define how low or high you sit in a seat or you may have a custom seat that changes your original riding height and position. Then we can change the posture of our riding by using the different BRP handlebars and foot peg position. Finally, your typical riding speed may be far different than somebody else here. Shields behave far differently for people who typically run back roads at 55 and under versus those on state routes running up to 65 and then guys like me who do spend time at 75-85 MPh in transit. So it is hard to go by other's opinions.
For example... I'm 6'2" with a 32 inseam (as if that is scientific in the grand scheme of this discussion) * I might have shrank a bit too.
Blue Ridge- Took the risk, paid the price. Blue Ridge made riding worse than with no shield at anything above 50 mph for me. Lots of head shake.
Guffanson(Spell?) - Some people liked this. Uses the existing Blue Ridge mounts. Looks nice. Anything near/over 65 Mph and I got a lot of head shake.
32" F4 Shield - Major improvement over 65 but still get slight head shake at 70 MPH+. F4 is nice and wide. Can't beat the quality of the shield. Mounting hardware is nice for mounting some RAM balls on. Mounting hardware should be texture powder coated though. My nose is level with top of shield on custom seat. If the F4 had the knurl along the top, I think it would be the perfect shield, but of course it does not.
So I bought this MRA X-Creen spoiler to clamp to the F4 to kick the air up at the top edge.
https://www.amazon.com/MRA-40250661...F8&qid=1494514928&sr=8-1&keywords=mra+x-creen
It is a bolt through, but I bought the clamp kit to test it first. I'm able to adjust the X-Creen to pitch the air up at the top of the F4 and now I have less wind noise and no head shake at 75-85 MPH.
The X-Creen of course has it's own issues for me, but I'm going to redesign the polycarbonate and just reuse the X-Creen mounts and end up with a better setup...and probably bolt the X-Creen to the F4.
So there you have it. Again, I think the F4 is a great shield if you spend most of your time riding under 70 MPH and you are my height and have the 32". ***But head shake is a very bad thing and you can't and shouldn't ride for long like that.
Just wish the F4 had a knurl or that F4 sold an Auxillary wing for the top edge. I'll have to make my own.