practicing sliding. How to get a great final product
 

YouTube - Slider 2 Test

Is this really bad and is this my technique or the 5d2 or ?

I thought the steak was a bit overcooked. :)

It looks a bit jumpy. Did you have stabilization on? If not, it could be the slider or technique. I think it takes some practice to get good slide, especially slow ones. The same is true with tripod panning - good equipment helps but you still need to practice.

What slider do you have?