Should I be using SQLObject, SQLAlchemy, or SQLAlchemy + Elixir?

I've been using SQLObject for a long while, but noticed that SQLAlchemy has become a lot more popular in the last couple years: http://www.google.com/trends?q=sqlobject,+sqlalchemy

Are there compelling reasons to switch to SQLAlchemy? How is its performance relative to SQLObject? Its usability? And what is the added performance overhead for using Elixir?

My needs are basic, simple CRUD. Nothing exotic.

I've seen this related question, but it was asked 1+ year ago and didn't have much response.