It was great if you were a smoker. If you weren't it was probably awful. The last rows were smoking. A travel agent friend had a client who didn't smoke but liked sitting in that section because he said everyone was friendlier & more jovial.
I joined American's Aadvantage in 1986. Upgrades were 10,000 miles for quite a while plus you got the mileage for the class you upgraded to. On my most frequent flights it was a wide-body and very comfortable. People did seem friendlier then. I recall a lot of fun on long flights. Of course, I was younger & hotter then which probably had something to do with it.