Even though I love both of the shows, and I love Nixie, I kinda think that H20 is a better and more enjoyable to watch show. Why? I'll list a few reasons.
I know this may seem like a weird reason, but just keep reading. In each show ( so far) there has been three basic personalities. The practical one, who might be a bit mean but doesn't easily loose her temper, the naive one, who might act kinda dumb or get pushed around by the others, and the hot-tempered one, who easily gets mad. Theres been some dispute on who's who with Nixie and Lyla, but everyone agrees that Cleo and Sirena are the naive ones. So why is Sirena the problem? Because she's a whiny brat. Cleo, though Naive, did certainly not cry in every single episode like Sirena did. All Sirena does is whine about everything, and it gets really annoying. I don't really mind the naive characters, but Sirena just makes me want to slap her. So I guess the basic thing here is: Both shows have naive characters, but only the one in MM ( Mako Mermaids) is incredibly annoying.
2. The H20 girls just get along better.
Other than the first 3-4 episodes, I can't really remember any other ones where all 3 MM girls were all together and agreeing on something. Its always Lya and Nixie vs. Sirena, or Sirena and Lyla vs. Nixie, or Nixie and Sirena vs. Lyla. Sure, there's been a few where they get along, but not very many. In h20, there were some episodes where they got into fights, but it was resolved and didn't really happen every episode.
3. Season 2 replacements
In H20 and MM, characters eventually got replaced. But replacing TWO characters and adding another mermaid seems like too much. They should've done another spinoff where Evie met Ondina and Mimmi. They're just changing the plot waaay to much for MM.
And on an unrelated note, I just realized you can make groups of three if you have all the mermaids ( Not counting Evie and Charlotte). Theres the replaced ones, Emma, Nixie, and Lyla, the ones who got to stay, Cleo, Rikki, Sirena, and the ones who replaced someone, Ondina, Mimmi, and Bella.
So what do you think? Is H20 or MM better?