简单的个人网站，数据库使用 mongoid，所以 AR 的新特性被无视了；Strong Parameters 对于小网站而言也没有用武之地；网站访问量低，没写缓存，所以缓存的新特性也没有用上。
目前看下来似乎只有 Turbolinks 可以尝试下？
各位有什么打算升级到 Rails4.0 后使用的新特性吗？
HTTP Streaming is another change that is new in Rails 3.1. This lets the browser download your stylesheets and JavaScript files while the server is still generating the response. This requires Ruby 1.9.2, is opt-in and requires support from the web server as well, but the popular combo of nginx and unicorn is ready to take advantage of it.