The Joby is ~$50 and the Slik is ~$80. And 14oz vs 28oz, I wish I had just bought the Slik and skipped the Joby.
A couple photos for comparison.
The camera is a Nikon D5100 with a 18-105 lens that weighs 36.45 oz. The ball head is solid enough that portrait mode photos were no problem, landscape mode was very stable.
The chair is a "normal" dining room chair to give an idea about height. Without any legs extended, the Slik is very compact and easy to fit in the side pocket of my pack.
With the legs completely extended
With the center column extended as well.
The legs have 3 positions (angles), this is the most extreme.
Middle position of the legs.
Steepest angle of the legs.