The creation of a context is a very lightweight operation and is not slowing the application down. Creating/Disposing a context does not mean opening and closing a connection. The connections are held in a pool which is on its side static for the application. When a context decides to perform a CRUD operation it just gets a connection from the pool and that connection is already initialized so you have minimal performance penalty for that operation. If the context is only created and disposed - it doesn't even get a connection from the pool so there is absolutely no performance penalty with that approach.
the Telerik team
Register for the Q2 2011 What's New Webinar Week. Mark your calendar for the week starting July 18th and book your seat for a walk through of all the exciting stuff we will ship with the new release!