We've been using this for what feels like 9 months with Picplum. One thing we did is for on select menus with few items, we hide the search box:

  $(".recipient_relation").chosen disable_search_threshold: 10

And if in Backbone you'd like to have it preselect the value, run something like this after render (so you don't have to add much logic to your handlebar template for the markup):

@$("#address_country_field option").each -> $(@).attr "selected", "selected" if self.model.get("address_country") is $(@).val()

It'd be nice to see some folks share their menu styles. The gradient on the select doesn't quite fit in with all site styles.