I'm using both Resophnotes and Cintanotes (syncing with two different Simplenote accounts). Resophnotes can keep all your notes in separate txt files, which is quite a unique feature. Files can be accessed and edited by external txt or markdown editors (as Sublime text, WriteMonkey, Focus Writer). I use RN for keeping lists, syncing longer txt files, and some personal (but not sensitive) data. I like its classical two-pane structure. + I can access the data on my android phone.

Cintanotes does not have it, and I use it as addition to Scrivener while writing my book. I put all the random information, bibliography information, fragments and ideas, that I don't know yet where to put. I know that I can do it in Scrivener, but it is slow, clumsy and really bad at handling bibliography. It's easier to keep the bibliography list in fast CT file.