How different is it going to feel stationary in a queue of traffic or doing 30 in a 40? On the open road of course it feels different but I hardly ever drive like that really
The biggest thing for me is that mine would sell for quite literally nothing and yet buying an M5 in the same condition as mine would require a top end example, so potentially 10 figure sum to swap one 2002 E39 for another 2002 E39 which is identical to look at and sit in and only different mechanically. I love E39's but... maybe not THAT much
I think it would take a forced change really, if somebody ran into the back of mine or something and I was forced to buy a new car then I might consider it.