Right cee bailey height for R1200rt

[bourbon]

R1200RT 2010. 6' tall, seat in lower position. With stock screen in almost full vertical position, I still get noise and buffering, I can see above the screen in any raised position. Because I have had very good success with cee bailey on 97' RT, and want to give it a try on the 2010. But, how tall? +2 or +3? I can't decide. I tried the method explained on their website, but it's not clear to me what "a quarter up" really is. Should I go for taller rather than shorter? Whare are the pros and cons? Anyone has similar experience? Thanks!