Not whom you're replying to, but I have had a fair amount of dealings with police in and around Chicago, mostly from traffic stops, but also from calling them/having had them called on me.

Most of the traffic stops have been for speeding (and I was speeding). It's been about 50/50 on whether I get a ticket or a warning.

I had one traffic stop in Chicago, south of the Loop on State Street, where I was pulled over by CHA (Chicago Housing Authority) for failing to signal while changing lanes (he lied; I always signal, kind of a pet peeve of mine, though I admittedly speed all the time). The same officer illegally ran a red light in front of me w/o his police lights on. What proceeded during that stop was an outright interrogation. Who am I, where was I employed, what I am doing here, etc. I told him that was none of his business and not relevant to the traffic stop. Told him I wasn't answering anymore questions without a lawyer. He threatened to arrest me. Didn't utter another word, just kept both my hands on the steering wheel at 12 o'clock. While he wrote the ticket, the other 2 officers that were with him apologized on his behalf, yet did nothing to prevent the ticket from being written. Guess I just found a dick of an officer on the wrong day. Also think I was profiled a bit. White kid, out of state plates driving through the projects. Pretty sure he thought I was trying to score some drugs, when in reality I was just going to college to take a final. The kicker is, they confiscated my license as bail. I was supposed to fly home for Christmas vacation a few days later, and my license was my only valid ID to fly at the time. I had to get a state ID that cost only $4, but I was in college and broke. I had to pay that $4 in dimes from my change jar because that was literally all I had.

I've also been pulled over by a sheriff's deputy in Montana before. I was visiting my parents around Christmas and I got pulled over for "an aggressive pass". I accelerated rapidly and passed on the right someone that was driving 10 under the limit in the left lane (illegal in MT, btw, slow traffic in the left lane must pull over tot the right). It was somewhat comical because the deputy turned on his lights at me, and I went to pull over, but it was in an area with next to no shoulder. I literally had to drive about 4 miles further, with my signal on as the deputy kept calling at me over his loud speaker to keep going until there was a proper shoulder. The deputy gave me a warning, despite my bloodshot eyes and breath smelling of whiskey (I had been up since 4am CPT, had been travelling all day and it was now 7pm MPT and I'd had a single drink with an old high school friend and I was still wearing contacts at the time).

When I've had to call the police, I've generally been treated fairly well. Most often, it's been because of a traffic accident (I've been in probably 20 accidents in my lifetime, only 1 of which has been my fault). Other times, it's usually been due to noise complaints against neighbors very late at night. One wasn't terribly late, but I was reading a book quietly in my old apartment and I could hear a woman screaming bloody murder. Literally heard through the ceiling "Help! He's going to kill me!". I don't like to get involved in other peoples arguments/disagreements, but yeah, I definitely called the police on that one. Another time, same apartment, I happened to be up late watching TV at like 2am when I noticed a ton of police lights out in the drive/parking lot of my apartment complex (at least 8 cop cars with lights on) and officers wandering around with shotguns, assault rifles and pistols drawn. I live in a pretty affluent suburb of Chicago and this is pretty unheard of around here. I asked the dispatcher what was going on, and initially they wouldn't tell me anything, but later relented a bit and told me that at an adjacent building, there was a domestic dispute and the suspect had fled and they were searching for him (it happened to be snowing pretty heavily at the time, so they were following tracks in the snow).

All in all, I'd say me experience with law enforcement has been positive with one really sour experience. But, then, I'm an affluent white male. That said, I think if you're generally compliant with instructions, you probably won't have issues (this doesn't extend to answering questions - you don't and shouldn't have to without a lawyer present).

A bit of advice if you get a traffic stop: don't immediately get your license and registration out. Just pull over and leave your hands on the steering wheel, in plain site. When the officer approaches your window, explain to them exactly where each requested document is. i.e. "my license is in my wallet in the left rear of my pants and my insurance document is in the glove compartment." And make sure they acknowledge that before you make any movements to retrieve said items.

Edit: forgot the bit about them being called on me
When the police being called on me, it's always been a noise complaint and only happened once or twice.

Both times, I was drunk and didn't realize how drunk I was and how loud my music was. Turning off/down the music solved it without any issues/fines/arrests.