Milani Gems on the left and Ulta Pinata-yada-yada on the right.
In my opinion the glitter in the Ulta looks more mirrored than the glitter in the Milani. The yellow in the Milani is really subtle, where as the Ulta is bright and gold. All of the glitter looks about the same size and I really like both. The blue glitter in the Milani is bigger than the blue in the Ulta, but the small blue glitter in Ulta is much darker. I think that both of these glitters are great! I just can't pick one, because they're each colorful in their own way.