before the bimmerland, i had a ford crown vic, with 4.6L V8, and 190 hp. that thing had hard time reaching 70 MPH and the speedo was maxed out at 85 (the cop version goes a bit higher). When i was pegging the speedo at something over 85, maybe 90 or something, the car was ready to go airborne.
then i got into an E34 530, a 3L small V8 that had that alusil problem... mine did not have that problem, but at 3L displacement, 210 hp and the speedo that listed 140 MPH, that car would hit 90 MPH like there was nothing to it...
The E39 528 that i got, with an I-6 and 190 hp (same as the ford's V8), the car was flying, but still, you could feel those extra 20 horses in the V8... it was very subtle feeling and I can't pen it down but with the X5 i went all the way out and got the 4.6iS... That was AMAZING!!!

About 6 months after me, my cousin got an E53 with I-6, which I drove around... In all honesty, the 6 is plenty for that car and what 85% (maybe more) of people will use it for... probably it is enough for me too... but approaching the mid-life crisis hump, i needed something in my life to excite me, other than a 25-year old wife and couple of girlfriends - I needed the wind blowing through my brain!!!
Being too practical to buy a Corvette, or learn how to ride a Harley, or a crotch rocket, I went for the V8, to supplement my male ego...

That is all to it... In Europe they used to sell 518, E39s with a 4-cylinder... Heck, they even had 720, a huge 7-series with a funky 4 cylinder... and people bought them and enjoed them... V8 is like the icing on the cake, most people don't need it and buy just because they want it... Of course, some people tow things with it, but why would you bake bread, or split wood (or other dirtying labor) in a tuxedo? there are other, far better cars for the towing... or, for that matter of fact, off-roading...

As they call this type of "SUV" in Russia - it is a "parketnik", meaning that this type of an SUV is designed for a ballroom parket floors...

My $0.02