The reason most of us use it is because we can keep our incubation substrate VERY wet. You don't have to worry about getting the right mix of substrate:water and just add as much water as possible. With the grate the eggs can still be placed at the same angle they were layed at, you basically just grab the clutch and place it on top of the egg crate. The only time you may have to separate any eggs is if the clutch is very tall then you may have to remove an egg or 2 off the top so it isn't in contact with the lid of the tub.
As far as maintaining the orientation of the eggs, they can be moved alittle bit when they are first layed. Also I have read a couple reports that it maintaining the orientation of BP eggs isn't as big of a deal as it's made out to be. A member Muddoc(Bailey&Bailey Reptiles) on here did alittle experiement with flipping eggs over to see if it caused any problems.
Here is the link to that experiement.
http://ball-pythons.net/forums/showt...%2Borientation
It wasn't a huge number of test samples, so not a "true" scientific experiement, but still worth knowing.