Especially in Chicago, which is very segregated, there is a lot of Black-White racial tension in poor areas. The terrible Trayvon Martin incident that just happened isn't helping either.
re: out of the past, I actually haven't been there that many times just because I didn't want to deal with it. Funk collector Dante worked there I think when he first moved to Chicago, I heard he was paid in records but I've never asked him about it because it was a while ago. OOTP has two things to look through. One is the upstairs which has tons of 45s, mostly crap. They do get new stuff in from people bringing in 45s, but I've heard that they put literally everything out, like Marie will throw away a box of beat up Collectables label 45s and her husband will get them and put them back with the stuff.
The other is the downstairs, which is a whole different experience. It's filled with store stock, most notably the lamarr / down to earth stock. There is heavy mold there (I got a headache within 5 minutes of being down there one time). They can give you a face mask if you ask for one. It has flooded more than once, making it even nastier. They have rats, which is why they also have cats, but you can easily encounter cat or rat feces or a rat carcass there. Anyways, despite thinking he cleaned it out, lots of people have pulled cool stuff from there since Dante worked there. At this point, though, if you're coming into town (especially from the UK), I would only go down there for the "I got my hands dirty digging in a nasty basement" experience without any expectation of finding anything great.
It is pretty funny that there might be a form of tourism which involves going into dirty, rat filled, moldy basements for hours, flipping through soggy stuck-together records.
Like any record store, they do also get good rare records in but (also like most records stores) certain people sort of have that stuff locked down...