The benefits from RadCompression can be seen on subsequent requests after the initial page load when the http requests are compressed. It is indeed strange that the resources served through WebResource.axd have such large size since only the ASP.NET AJAX resources served through System.Web.Extensions should be streamed - the rest should come from the Telerik CDN.
Can you please verify that you enabled the CDN as explained in this article
(depending on the .NET framework you run) and they are not served locally from the assembly? If the behavior is still the same, I will appreciate if you provide some input for the served resources on the page using FireBug or other profiler. Thus I will do my best to advice you further.
the Telerik team
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