I dunno, I still say it takes away from the impact. That's why the Machete order works; first you get to know the world of the Jedi, then you get to see them at full power as a backstory only for them to fall with RotJ promising a return and triumph.
Apart from any emotional attachment to the characters and events and just looking at the storytelling.
Then again, I don't know of any prequels that do not suffer from the same. You wouldn't want to watch Prometheus before Alien, nor would you want to read The Magician's Nephew before starting with The Lion, The Witch and the Wardrobe.
And even trying to get through the Silmarillion without even a passing knowledge of the world as presented in The Hobbit and The Lord of the Rings would be almost impossible and certainly not as rewarding.
To me, publication order almost always beats chronological order (unless it's a tv-series where the network screws up the order).