1.Perhaps the most obvious and important thing to notice is that when wet and damp (how it should be used) the original BeautyBlender actually grew much larger than when dry. The dupe grew only a little bigger.
2. Another obvious observation is that the material itself is different. The original BeautyBlender has a soft sponge like material that is very easy to squeeze and manipulate, which is exactly what you want since your face is not all one surface or shape. The dupe is a thicker sponge like material that is a little tough to squeeze when damp and almost impossible to manipulate and squeeze when dry. Definitely not a good thing for trying to spread product in hard to reach areas like under the eye and around the hairline.
3. The third observation is that the “dupe” retains a lot more water even when dry and can sometimes cause an uneasy or gross stench because of the dampness.
4.The dupe also makes it harder to squeeze the point at the top if you need to get really close to the under eye area. The original BeautyBlender squeezes so close together so that you can get very close and do not end up poking your eye.