This was really an interesting thread to read. I don't know what I would pick. I love to run outside when it isn't too hot and I'm physically able. When I go to the gym I spend 30 minutes on the treadmill and 30 minutes on the elliptical and then reward myself with 10 minutes in the jacuzzi. I travel fairly frequently for business and have found most hotels have treadmills in their 'fitness' rooms and the better hotels have ellipticals, too, so I've seen a variety of brands of TMs and Ellipticals.
Thinking about it.... I love running on the TM because when I lose my balance I can catch myself before I fall. I use the TMs on the back row so I don't scare people. So far, none of the trainers have noticed me or approached me because I'm invisible.
The Elliptical does give me a different workout and the advantage is that when my legs give out I can use my arms to continue the motion and my workout, so I'm getting a good upper body workout.
I love to people-watch at the gym. There are the socialites - in the 'right' clothes and chat for about an hour (usually right in the middle of the track or flitting from one area to another), glance at their watch, wipe their brow, and then, I think, go home. Then there are the First Timers - very tentative about the equipment, but they are Gonna Do It. I always quietly breathe the prayer "go go go" and "keep it up" for them. There are the Gym Rats. I don't think they'd come if there weren't any mirrors. There are the high school athletes, girls and boys. They should be banned. Then there are Us. I can always pick Us out. We're the ones in the clothes that don't match but we have Serious socks and shoes. We go straight the equipment - whether cardio or weights - and get down to business.
Oh. Back to the original question... I STILL don't know what I'd pick!