I also had the AC blower noise problem. Henna Chevy in Austin attempted to fix it this past weekend according the solution recommended in the technical service bulletin by replacing the control head on the AC blower. It actually made the noise problem worse and screwed up the outside air exchange (I now have a constant stream of hot outside air mixed with the cooler air conditioned flow). However, the worse part is that they were unable to get the dash back on properly rendering my coin tray and cup holder inoperable (they now stick). My advise is to not mess with it and live with the slight noise unless you have access to really skilled SSR mechanic.
Mine is in the shop today for the exact same problem!
So there are previous threads mentioning 'noise' mostly on fan setting 2. I took it in to get fixed last month because I was approaching 36k miles and the original warranty would be up. After the dealer fixed it the first time, there was a constant whistling any any fan speed. The dealer opened it up and filed down some plastic piece and the noise stopped. But I did notice that air constantly blows in now even with the fan off...the faster I go the more air that blows. So that's what they are trying to fix today.
SSR-Club: As for there being LITTLE or NO air coming out of your vents, I had this problem too after the dash was taken off for my stero install. The tubes that deliver the air to the vents on the dashboard just push up against the dash, they are not 'connected'. So unless it is put together correctly, the air will be just blowing into the back of the dash instead of out of the vents....I now check all 4 vents every time the dash board has been taken apart.
The other thing I noticed this weekend is that my large drink holder clip on the passenger side is starting to split. I know this is due to placing 20 oz. drinks constantly, as I travel a lot and require caffiene to keep me awake on my drives.
I asked the dealer if he might be able to just glue it, but I doubt that will work.