I used the leather rejuvenator the first time on the leather because it felt hard and brittle to me. Now I just use the leather care every couple of months to maintain the leather. You should notice a big difference in how soft the leather becomes after using both products.
I spent a lot of time on the leather when I first got the LC. I bet I spent 10 hours applying the rejuvenator in 3 light coats. The LC does have a lot of leather inside. Good luck and let me know your results.
Basically, I would do the front seats and the back seat and then go back and wipe off with a clean lint free cloth. I have my third row seats in a closet in my house so those don't need it nearly as often.
I would say it takes a little over an hour to apply the product to both the front and back seats and then probably another 45 to buff it off. Leaves a great smell in the truck. Speaking of, think its about time I put on some more of the leather care....