As for the 740, you already have the same engine, so I don't think we need to talk about that.
I've got a 1997 740i, and often wish I got the 740il instead. I'm tall and on long trips, which is really what I use the car for, I wish I had the extra room.
I've got to tell you, I own a 535im and the 740i, and I enjoy driving the 535im much more. I know a big part of the reason is, I've set up the 535 with a very sport suspension. The 740i, I've only installed Bilsteins on. The Bilsteins do make the 740i much sportier, but then it's got no manual tranny (I love a good manual).
The 740 is very solid. I replaced the thrust and control arms at 100k miles, and did not need to do it at all. The old ones looked and felt new. I just assumed they needed replacing because of my experience with the 535. There was nothing wrong with the ride or handling prior to replacing them.
The only nagging item in my opinion is the digital computer display on the dash. Pixels go in and out constantly. Sometimes they are all visible, sometimes you can't read squat! There's supposed to be a fix for that, but I just need the time to figure it out.
It's an absolute great highway cruiser and I can't see ever getting rid of it. Good luck.
Oh, btw, I've always thought that if the tranny went out on it, I'd convert it to a manual. But then again, it's always good to have at least one car with an auto tranny, just in case you screw up a leg playing b-ball or something!