The following factors should be considered when buying an elliptical cross trainer or elliptical rider:

Resistance
Every elliptical machine has some form of adjustable resistance. The best offer electronic versus manual resistance.

Incline
Various incline options come with any good elliptical trainer. Again, look for electronic incline controls so won't have to stop to make mid-workout adjustments.

Workout Feedback
To get an efficient workout, it's important to track your progress. Speed, distance, time-they're all important. Make sure your elliptical trainer has these three at the minimum. Other displays can include pulse, resistance and even calories burned.

Upper Body
Many elliptical training machines come with some form of upper-body mechanism. In order to get a total body workout, upper body exercise is essential.