I'd bet it doesn't do the same good as walking. As for walking, we live in a semi-secluded area and I'm just too afraid to go it alone. DH's takes him out of town often, and he can't walk with me regularly. That's why he got me the Gazelle.
I don't keep my actions to a single swinging motion. I push forward, pull backward, and stretch my stride. I also place my hands in various positions, which gives me stretch variances. I like it because it doesn't hurt. I can work up a sweat, tho. Every so often, I pull out my Total Gymn to give my muscles a work out. Haven't had it out since before the holidays... hating myself for that!!!!