Every so often, a person will ask a 540i vs M5 question, and with the current values of both cars used in the US, they usually mean E34 M5 vs. E39 540i.
Lots of people respond, and the consensus is something like this "the E39 540i makes more sense to the brain, but the E34 M5 makes more sense to the heart" because the 540 doesn't have a maxed out racing engine under the hood and the E39 chassis is more sophisticated, refined, and has more amenities.
I have come to the conclusion that for me, the E34 M5 makes more sense even to my brain, and here's why: What I'm looking for in my next car purchase is something that is a bit more refined than my Camaro Z28 - i.e. a bit quieter, a bit more luxurious, a bit less noise vibration and harshness, and oh yes, it must have at least as much horsepower as the Camaro
(factory rated at 305bhp).
The E39 may be a technically better chassis than the E34, but I have an E34 at my disposal right now, and it has the level of refinement and equipment I desire (doesn't wear you out on a 500 mile trip, very comfortable cabin, trip computer to play with, lots of gadgets) plus I absolutely LOVE the way it drives (For example, the ol' 1991 535iA has a better combination of ride and handling than a 1998 Lexus LS400 or a 2002 Acura 3.2TL) - It would be perfect with a manual tranny, more power, and a bit tauter suspension, with load leveling to prevent the slight sag in the back that comes with a full load of passengers and cargo. So the only logical choice is to buy an E34M5
Does this make sense? I think that all this means I would be better served by an E34 M5 than by an E39 540i, even though many others are really better off with the E39.
And did I mention the E34 looks 10 times better than the E39?
Don't tell the guys in the E39 forum