Watch this great video on a Procomp MX-6 shock installation on a Jeep Wrangler JK.
The reason we wanted to try these out was the ability to adjust them as we do a lot of driving either on road or off-road so we wanted to have a ride change when needed. And second was the monotube design was a little better for us when off-roading.
A monotube shock has only one cylinder versus a twin tube shock and has less performance fade. This allows us to have more shock performance when off-roading.