I just finished mine up as well. Cheap easy way to clean up the underside. Will do the rear axle/suspension/control components next weekend. Wire wheeled and degreased them, used self etching primer, coated both sides with Por-15 (I added UV stabilizer to it. Did the same thing on the underside of a Mustang I did and it never degraded in the sun)
I also added undercoating to the top surface (the side to the engine/trans).
Looks so much better than the rust it was covered with before.