I’m sneaking around on Apple Notes myself at the moment. I feel bad about it even though I’ve got a good excuse. I’m temporarily without a Mac, so I can use Notes on the iPad but I’ve nothing to sync it with. For that reason I’ve started to use Simplenote again, having tried it out very briefly in 2010. It will sync with my work (Windows) notebook. [Edited to remove reference to Arial font. In fact, Simplenote’s iPad app uses San Francisco.]
Simplenote has Markdown support now, which more than makes up for the absence of rich text formatting.