Ergonomics, weight, and glass quality will have some bearing on this as will how a binocular will be used. Considering those factors and magnification, I've used only 8x and 10x binoculars in past thirty-five years.
Some claim it's more difficult to hold a 10x binocular steady in comparison to an 8x. If that's the case, 8x would certainly be the way to go. Otherwise, I've never seen a disadvantage to a 10x binocular for general use.
