Are light movers noisy?

I'm planning on getting something like this:

http://cgi.ebay.com/Light-mover-Light-Track-System-6-for-Reflector_W0QQitemZ320441734607QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4a9bd0d5cf

For you guys that have light movers, what kind of noises do they emit?

don't get that one.
it is a cheap imitation of the hydrofarm light track which is the same price.
they even put a hydrofarm hood in the picture to make you think it is a hydrofarm mover, but it isn't.
i have the 4' hydrofarm track and like it a lot.
i have had the chain pop off the cog a few times, but that was because my ducting was twisting the hood.
as far as noise goes, it makes a light humming noise.
a lot of the noise form my setup comes from vibration though,
i have the track mounted straight to a 2x4.
if i were to do it again, i would put some sort of shock absorbing material between the track and the 2x4.
overall, the unit is quiet though.

i think that the itellimover light rails are probably a better product than the hydrofarm ones.
i have no experience with them but their design appears to have fixed many flaws in the hydrofarm track.

the hydrofarm track is cheaper and comes in a 4' size, which is what i needed.

Are there any major flaws in the hydrofarm track? Because I'd rather go with something cheaper