Having owned and used one of the Glidecam series units I can say that properly adjusted it works with both elements of movement, and does it well. Also, it is much less expensive, comparatively speaking, to the Steadycam series. I've not owned, nor ever used or tried, any of the major Steadicam series units, only the Steadicam JR which also employs a gimble mechanism and mostly addresses horizontal movement, but also allows for some vertical stability. However, the JR was highly susceptible to wind and a bit of a challenge to control when turning corners or twisting around. The force of the left-right movement made the unit want to continue swinging around after ease to a pause.
F.Y.I the Glidecam I owned was the Glidecam 8 series, complete with harness, arm and stabilizer. Both units required stamina for extended use and even with the brace and harness apparatus the Glidecam quickly begins speaking to your lower back region.
At the time I acquired it the Glidecam system was more than $3k. I don't remember WHAT I paid for the JR, but it wasn't cheap by any stretch of the imagination. Neither are miracle workers, and both approaches require some muscle development, stamina, conditioning and working out with in order to achieve their ultimate capabilities. Neither of the two I used were pick up and go type systems, calling for much practice to get it right.
Also, did I mention that these systems, especially the more effective ones, are pretty darn expensive?
On another thought, after having worked with these, I've learned to achieve some smoothness in motion with one of the heavier monopods, using a thumb-and-forefinger grip, slightly extended arm acting as a shock absorber, and a slouching, Groucho Marx type quick shuffle walk to reduce the naturally occurring bouncing motion in normal walking. Most monopods of any weight will help achieve the balance needed once you get the hang of the grip, especially for short distances.
