Most CAI's wont make a difference unless you use a tuner to let the computer compensate for the extra air. Plus with the use of a K&N, be prepared to have a dirty throttle body. I warned my friend about the use of one of those and he could not believe how nasty the throttle body was. Totally caked with dirt. He took it off immediately and put a regular filter back in, just as I did the same. Just try to find a quality air filter. Hopefully a tune will be available for the turbo in the future. That will make the most difference as turbos are very responsive to tunes.
If you want to have to use stuff like Seafoam and what not on a regular basis, then use a K&N air filter. I prefer to use WIX or Mann air filters. I'm not going to risk having my cylinders filled with dirt. I already saw other people who used K&N filters that had their throttle body's with dirt. I promptly removed mine after seeing this.
Initial impression is that there is a bit more pick up from stop. Engine noise is largely unchanged. The filter seemed well made and more "oily" than other filters I have gotten in the past. Jury still out on mileage, though it has only been a bit. Noticeable improvement when trying to squeeze into a tight space going into an intersection.
You've made this point several times. Other people feel differently and have been waiting for a filter to come out. Personally, I have not had an issue with their products in the past and have noted some minor gains. This vehicle needs all the help it can get in terms of pick up.