Anyone bought / have an opinion / review for these cheap motorized pan-tilt heads?

Would they perform well at the end of a jib/crane? Smooth etc?

Motorized Pan&Tilt Surveillance Head for Camcorders (eBay item 150570158849 end time 30-Mar-11 13:39:52 AEDST) : Electronics (http://bit.ly/folbIj)

AND

MP-101 Motorised Power Panner Pan Tilt Head For Cameras (eBay item 130344505486 end time 09-Mar-11 22:20:30 AEDST) : Photography (http://bit.ly/enqDXG)

Would love to hear from anyone who's bought one!

Thanks.

not bought those specific ones but the second one looks like the Bescor I have and only used a few times. For palmcorders and gopro/contour size cameras, you might get some use out of them but don't put a mid-size camera (or heavier) on one as the motors just can't keep up. The Bescor is very jerky. Plan on editing around the start/stops of the movement.
I don't feel too bad since it was such a cheap purchase. I am planning on a PT20 to go on the end of my Kessler though!