I have noticed on my Adept, that my abilities that i rely on that are based off of Qi Foci tend to go by by when the background count gets above 1-2. which i believe is most everywhere in the CZ if memory serves (minor places might not but main areas yes) mainly i remember that i can no longer use my Force 4 Qi Focus for Astral Perception. which really sucks when your trying to do astral combat....
That impression seems incorrect for Missions. I played the raw versions of 5-02 and 5-03, and do not recall them throwing the Background Count to 4. Only 1 Mission had this, namely Humanitarian Aid at the worst point, which is not Chicago.
I checked the finalized versions. The base Background Count and Noise in the CCZ is 2 and 2. In the first three Chicago runs there is a 3 Noise once, a 1 Background Count once, and that's the only exceptions.
In the raw versions of the next three, which aren't out in finished format yet, there is only 1 exceptionally high background count and one I suspect will be toned down given the finalized Background Count rules.
Honestly, I'm surprised that the background count for people goes past 2 in Chicago, because there is only 1 Chicago Mission out of six with that, only one out of eight 2010 CMPs, and none out of eight 2013 CMPs. Granted, I haven't seen the second batch of Chicago Missions yet* but even then I would not assume it's a really frequent occasion.
*: I am going through filler CMP Missions in the hope 4~6 release before I run out of filler Missions, since I want to run them with finalized versions.