Yes, certainly - I studied all this. Up to everyone what they chose. With all due respect - the original are available in the form of USD 100 worth of piece of cardboard with black "pebble" pattern on one side - for you to cut, apply foam etc. Not worth it in my view.
The original originals, well, may dispute how they looked. Especially with those holes - I agree here with 66andblue.
The Niemoller or SLS pieces - ok, but they are around EUR 150-200 and come black. I think I would prefer the same looking material as upholstery, even though you merely see it, and a bit better soundproofing - that is why the decision to do those myself. Not to mention cost, which is about EUR 30. A bit more pain in the back, I suppose, as there is a bit more fitting to do.
And it creates ground for more bonding with the car, which is priceless.
Pawel