I just bought my girlfriend a 97 840ci from the 2nd owner who obviously took very good care of the car. I really went over all of his maintenance receipts and, while not Honda/Acura reliable, his costs for 8 years of ownership were much lower than I had previously been lead to believe were the norm. The early 8-cylinders (the 4.0 engine) had problems with the nikasil cylinder linings and sulphur in the gasoline. BMW replaced quite a few under recall and the 4.4 resolved the issue. I always loved the looks of the car and now my girlfriend absolutely loves the luxury, 'soft ride', and the power.
My NSX is a 97 that cost about the same as this one when new and they are about polar opposites. There were actually fewer of the 8-series in the US than NSXs imported. The 840 weighs more than 2 tons but handles remarkably well for its size. The pillarless windows make for a great cruiser and it is stable and quiet at amazing speeds. Even the 8-cylinders are good for over 180mph with the limiter removed. When she lets me drive it, I find it to be the perfect complement to the NSX. Definitely not for everyone, but a special car in its own right.