Using CDN (ie. Rackspace) for hosting website Javascript & CSS - quicker page load?

We're relaunching our website and the new site is being hosted on a dedi server @ Softlayer.

We're also using Rackspace, to host our documents etc, however...

My colleague has also put the websites JavaScript & CSS documents onto Rackspace, as well as the sites images. This, he says will mean quicker page loading times (and also saving money on bandwidth)

Now I am not sure what the bandwidth charges, but in terms of page loading, is this correct?

I would assume that the documents being hosted on the same server would be quicker (same Nameservers etc) than fetching from an external provider, but I may be very wrong.

The website won't be used internationally, but we have ~10,000 members which would use our interactive site.

I would appreciate your comments / discussions regarding this.

Thanks! :)

Solution

This has been discussed N times here and there. As you pointed out, you save bandwidth and, if it used wisely, will boost your loading performance. That is the good thing. However it is positive that when you use it you take into account that:

There is an implied external server response time to your GET request.
Client may eventually block the CDN provider.
Ideally, CDN servers must be located near your main user base to get the quickest response possible.
You have to be careful on how many requests per page you do.