Lots of people like to compare these two senshi, Sailormercury and Sailorneptune. Their powers are somewhat similiar even though I think Sailormercury's powers are more related to ice.

I really hate sites that always pit these two senshi against each other. Yes, I think Sailorneptune has stronger attacks, offensive wise. But in the anime, Neptune only has two attacks. Sailormercury has four. Sailormercury's attacks are not as strong as Sailorneptune's for a reason. They have different missions. Mercury's mission is to protect the princess. Neptune is responsible for guarding the solar system. So she would have stronger attacks. Sailoremrcury shouldn't be estimated though. She has a variety of attacks that can be used for different things. She also has a visor and mini-computer. Even, Sailoruranus, Neptune's partner, complimented Mercury's fighting style.

In their civilian forms the two girls are somewhat similiar. They both are serious and intelligent and like to swim. They both seem to be patient and levelheaded. In terms of looks I think both girls are equally beautiful. It depends on what you look for.