Loops are just loops made of Invisible ELASTIC Thread. Normal Invisible Thread does not stretch, but there is a variation that does - IET.
I prefer both. They are used for completely different things. You would never use normal IT for a loop, nor would you use IET for the sort of stuff you would use IT for.
I think Haunted deck looks better with loops because of the elasticity. It looks a bit less connected to your hand because you have slightly more range of movement that causes the deck to move, which I think makes it more deceptive. But Eugene Burger did a really nice and simple version with regular invisible thread - so indeed, either work.