So the e24 is sexy, there's no argument there. It is also a very logical transition from the e9. However the e24 has a very different feel to its 4 door counterpart which is the e28. The e24 and e28 were eventually built on the same chassis; so one could think that they would have a similar feel and drive. This is not the case. The e24 starts out with heavy clunky doors, almost Trans-Am like but not that bad. Getting in the car, the seat position makes you feel like your belly is pointing at the ceiling. The dash layout isn't very cohesive and the vents are so far away that by the time the cold air reaches you it has been heated by the heat soaked dash. The drive is almost muted and really doesn't offer good feedback. This along with the seating and steering wheel position make it almost awkward to drive. And the greenhouse leaves a lot to be desired.
The e28 on the other hand, and don't ask me why since they are on the same chassis, is completely different. The seating position, instruments, dash, etc... are well laid out. The seating position is right where it needs to be. Feedback is excellent, and the a/c works well. The drive is so different that you almost can't believe they are built on the same chassis with the same suspension and drive line. Visibility is excellent. One avid owner/enthusiast once said "the e28 doesn't do any particular thing extremely well, it just does everything really well.
I've had both m30b34 e24s and e28s as well as s38b35 (US m5) and m88 (Euro e24) variants of both models. The e28 is hands down the superior car, in every aspect.
How does this compare to our e9s? The e9 is definitely a product of the 60s (European). Obviously the exterior design is beautiful; but the interior of the e9 is really attractive and the seating is definitely for the driver. The detail of the interior with the wood and bright work is really of high quality and nice detail. The e28 and e24 lack that and really are Teutonic which makes them more purpose built, Germanic. The drive line is standard BMW M30+Getrag with a nice exhaust note and excellent independent suspension. Those of us with the 3 litre version can really appreciate an excellent braking system. Back to the interior though, the business section. It is a really good seating position and the layout is really simple but really good. The steering wheel is right where it is supposed to be. The pedals too. The speedo, tach, and other gauges are also right where they need to be. The shifter is in the right place and everything is really where it supposed to be, even the cup-holders. The greenhouse is excellent. Visibility with all that big glass, low lines, and thin pillars (there are only 2 per side) really makes pointing the nose and catching the scenery a real pleasure. In all a great car to drive with excellent feedback and performance.
If I had to choose just one it would be really tough to decide between an e9 and an M version of the e28. Both are so well engineered and both offer their own personalities; but I think the e9 would win the coin toss simply because it is so beautiful. Drive is close to equal to the m5 other than an extra cam and twice as many valves. Minor details...
If you have the opportunity to spend a little time with an e24 and an e28, I think you'll agree the e24 will leave you a bit disappointed. Sorry to all the e24 out there.