I own a 97 E320. 1st I'll list the positive points:
1. smooth I6 compared to ticking v6 (98+).
2. Quiet and fast 0-60 6.7
3. If you have ETS it disengages after 25 mph, thus you can still play around.
1. 1st year of the 5 speed gearbox in the E320. No failure problems, but I have heard some faulty computers. No problem w/ mine
2. Infrared key no radio signals
3. Head Gasket and Oil seal leaks-no leaks on V6.
I have driven both, the I6 sounds really good while the V6 will roar but not quite as spectacularly. The 3V V6 is my reccomedation for you if you live in the east. Supposedly the cats heat up faster w/ v6; thus faster cold immediate performance. Also it has a far superior ignition spark system, two coils and two sparks per cylinder. But if you are like me and live in So. Cal., I would reccomend the I6. The 5 speed is telepathic. If you wanna drive fast, it'll shift crisply correspondinggly. If you wanna go slow, shift unnoticeabley. It can go fast when pushed.