I got the windshields in week before last, and promptly went out of town for the Zero to Hero thing in Vegas. Tested out the V-stream last week, and rode in today with the CalSci installed. Experience pretty much mirrors what everyone else here has said, but I'll do up an eval anyway.
Bike: '09 - with the Kawi Touring shield installed since new (I bought the dealer's test-ride bike and they had upgraded). As I understand it, the taller shield is the same as comes stock on the '10+ bikes. Also, I've got a Baldwin Saddle that I think sits a smidge higher than stock due to the upgraded foam. Also, I have a Givi E52 that I always have on the bike, which may play into the backpressure issue I'll mention below.
Rider: 6'0", 32" inseam. Shoei QWEST helmet.
V-Stream: As others have said, this thing is only a bit taller than the '10+ shield but due to the 'V-bubble' it arcs further away from me and appears a LOT larger. With the shield fully up it's nearly dead quiet from the rider's seat. However, it moves around A LOT in anything other than clean air (crosswind, following other vehicles, etc). I can see over the shield when it's all the way up, but have to look through it for lower speed cornering and when in traffic (i.e when I'm not looking way down the road. I could probably get used to that, but the movement thing weirds me out quite a bit. I didn't put my wife on the back with that one, as I wanted to test both shields and see which one I preferred before getting her opinion from the back seat.
CalSci: Being the medium it's very nearly the same size as my current shield, but it makes a big difference in wind noise. If I drop my head 1/2"-1" I can get into the same near dead quiet pocket as the V-Stream. I'm going to try it out with my wife on the back and see what she thinks. I might try and copy the cutout from this shield onto the stocker and see if I can get just a bit more 'loft' with the air coming off the top of the shield. Based on it being very similar in size to my current shield, I think with the added cutout on the stocker I might not need to invest in another shield. If not, I'll probably grab a CalSci large since they're 1.75" taller and should eliminate having to drop my head to get into the sweet spot for wind cutout.
I'll post back here once my wife chimes in and then box them up for whoever's next (list is currently blank).