The install is easy if its a 5-speed, more difficult for a auto since you have to go under the car and hold the flywheel from turning when talking off the crank bolt. You will also need a gear puller to take off the crank pulley. Its not like the old 5L where you could give it a light tap and it falls off.
Performance wise, the Steeda UD pullies and TA were one of the better mods I ever done to a 4.6L engine. I run 13 degrees of timing on 87 pump gas and got quite a boost in hp and especially low end torque. So far, no pinging with 87 octane. Lucky I guess.