Well it really is up to you!
PPL only do it if they wanna make there engine bay look good i guess!!! No Performance Gain out of it!! To much hard work i say!! Not like we look at the engine bay whilst were driving along and other ppl seeing the work you have done when its under the hood whilst driving!
Waste of time unless you want it a show car!!! Spare ya hands bro from sanding and give your car a hand polish for a bit of shine, cause you will get more looks from that instead of a New looking Plenum hidden underneath the bonnet!