I have had only bad experiences with Fel-Pro valve cover gaskets and any sort of silicone sealer. They always leak for me, and do so quickly, and they are trash as soon as you take the valve cover off again. Since the valves on these engines have to be adjusted periodically, that is a problem.
All the times I've opted for factory valve cover gaskets, on this car and others, I've had good results. The rubber that's used in the original valve cover gasket does not seem to deteriorate unless the engine is overheated, and I have seen zero issues with factory valve cover gaskets leaking.
A mechanic will always want to replace the valve cover gasket whenever the valve cover comes off for adjustments, however I have not yet had to replace the factory valve cover gasket after adjusting valves. My trick with that is to make sure to completely clean the gasket and the mating surfaces so they don't have oil on them before the gasket is reinstalled. Naturally, I always look around for oil leaks whenever I have the hood open, but I have not yet seen a leak from a factory valve cover gasket that I installed.
It might not seem like a big deal to replace the gasket whenever you adjust valves, however it is very easy to get in the habit of procrastinating on a maintenance item because you don't have a replacement part in hand. Knowing you don't have to replace a good valve cover gasket to adjust the valves makes it a lot easier to adjust them on time.
Not having leaks is nice too.