I travel a lot and use the equipment available at hotels and YMCA's around the country. Over the past couple of years, my ankles have expressed a preference for ellipticals. The ones made by Precor seem to have one of the smoother motions. I like the ones that have a heart rate function built in, not one that uses fixed contacts, but receive signals from Polar X-mitters. I have a Polar that I use with my home rowing machine (Concept 2). If you have some flexibility in your decision about type of machine, you might give a look at the Concept rower. The motion is smoother than an elliptical, works the entire body, doesn't need a power source (except for a D-cell battery) and you'll never wear it out.