I think you made the right choice. I belong to a gym and use the elipitical trainer and the treadmill. The elipitical gives me more of a work out, and I can burn twice as many calories than the treadmill, although I've heard that the elipitical may not burn as many calories as it says it does.
If I were to purchase one piece of equipment, the elipitical would be it. I could put it in my bedroom, on the upper level, and not worry about the pounding on the floor. Takes up less room too.