I had samples of both the Milk Ubame mascara and the Marcelle Xtension Plus Curl. I applied one to each eye and did a side-by-side comparison. Both gave lovely, long, curled, and slightly feathery lashes with good separation and minimal clumping, with the Marcelle elongating my lashes slightly more than the Milk. The Marcelle applicator was significantly easier to use than the weird Milk bubble wand. After drying, I tested smudging by gently swiping across both eyes with a cotton square. The Marcelle left almost no residue, but the Milk left a noticeable smudge. Neither is waterproof, but to test how messy they would get when wet I splashed a bit of warm water on my face. The Marcelle gave me instant raccoon eyes. The Milk didn't run much, but made my lashes clump together. Both come off easily with cleanser.
Conclusion: Marcelle wins on ease of application and smudge resistance, but Milk is a safer bet if it might get wet