How much of a time/comlexity win can I get from using a JS framework (vs. vanilla JS) for prototyping a Reader webapp's UI?

By Reader, I mean an app that has a UI vaguely similar to the old GReader, or Gmail. I realize the large complexity of these apps under the hood, I'm just talking about getting a simple UI MVP: folders with read/unread count, items in the folders with read/unread status, clickable to expand a simple textual body. It'd be really cool if it'd also work on mobile (at least on Chrome).

Which framework would you recommend?