1. first I absolutely loved my silver/grey 1995 840Ci bu the car had 94k miles and was out of warranty. The engine problems (nikasil) also coevered until 100k miles so I had a few months to do a change. The car was in a perfect shape in every way and was beautiful.
2. The transmission had the harsh shifting problem and a front suspension needed a few changes (lower control arm and a few bushings)
3. I test drove a 1997 840Ci (same color) and loved the engine with a shiftronic transmission. It gives you a little back from a manual feelings.
4. I found this very nice and perfect white 1997 with 26k miles and full warranty ! The price difference was about 7k USD and I felt like it is worth it. I have a bigger (stronger) engine, a steptronic transmission, a full free warranty, 70k miles less in my car and all of this for 7k USD and a change from silver to white. Belive me for me this was the biggest price to pay I loved the silver so much... I hated the interior in the white, but then my idea hit me - swap the interior ! I did the change and now I have a white with grey leather and also created a first silver car with tan leather. I sold the silver and kept the white car.

The transmission alone isn't worth the change ! The engine is a little stronger but really not that much ! The worst chip upgrade can do the same increase in power what the 0.4l did for the 96+ 840Ci.
I think if you are happy with your low mileage '95 and no engine/nikasil problems are bothering you then stick with it. Not a single change in a 96+ is worth the extra money such change requires. I had only one more reason, the 97 was the last production year for the US. So now I have one of the youngest 8 series... not that it matters at all. My car is not stock I never wanted to keep stock so it is not a collector item. I drive it every day (almost) and have drove it on track, autocrossing, etc. I keep the car in a mint condition, everything is perfect on the car ! I love my car and want to keep forever and now I still have a low mileage car not with almost 100k mile.

check the whole story at http://moree31.homestead.com/lez.html