Is extremely slow...

In my view it nothing do with the client at all. Your server is slow. Try switching to production mode and see if it is this slow as well. If this doesn’t help index the columns of the database table you are using for autocomplete thing. If even this doesn’t work try hosting the application on another server(faster).

In my view this is nothing to do with client side things like browser, machine and JS libs.

Try also using firebug - it's great for seeing how long the browser
waited for the response etc (and for a whole host of other things)


OK, I will try them all and see what happens. Thanks a lot everyone