I'm 5'11" and tall torso'd. I have the CalSci Med screen with oem wind deflectors. I've ridden in plenty of rain at speeds from 60-80 for sustained periods.
First, I like some air flow, so wasn't looking for a totally quiet 'pocket'. CalSci's web site suggested I get the large, but I went for the Med. I think the Large would give me that fairly quiet pocket, but the trade off is air flow.
The quality is very good and clarity/optics are excellent. No fitment issues on mine.
With the Med screen, I get no air flow to the neck area. I like to open my jacket collar when it's warm and let air balloon up the jacket so the venting works better and it keeps me cooler. With the Med size screen, this doesn't happen. I'll likely pull the screen off and put the stock one on soon, since it's warming up. The first ride with the Med I noticed that at humid temps below 60F, I also didn't get enough airflow to my helmet vents to keep me fog free with the visor closed, (I did with the stock screen). I've gotten used to having to crack the visor open when it's cold, but don't particularly care for this when conditions would not normally require me to use my Pinlock visor.
I do not find that the hole lets in a significant amount of rain. I do have it mounted in the low position, (no extra holes drilled by me), and there is no big gap at the bottom. The cut outs match the hand guards, allowing full lock to lock bar movement.
If you're mostly a fair weather rider and the airflow to your head/neck is not an issue, but turbulence is, it's a good choice. I'm curious about the parabellum screens, as they claim mpg gains too in some cases. They have some opinions I don't share though.