An elliptical trainer was my #1 piece of equipment when I lost about 40 pounds 9 years ago. Likewise, I had an uncle who swore by an elliptical as the reason he lost over 50 pounds. I think they're great for someone "not in shape."
There is definitely a "curve" in the beginning. I found in the beginning I could barely make 10 minutes. But I kept at it and then POOF! all of sudden I broke through this barrier and was suddenly doing 30+ minute workouts.
My personal preference at the gym is the Precor machine that allows you to adjust the incline but does not have the arm workout. Since I like to do interval style workouts, I find it easier to adjust my intenisty on that machine than the others. Still, I like the ones with the arms too.
And since I don't own one at home (at least not right now), I can't really comment on that part of it. But good luck!